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Unable to start activity: NullPointerException [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 8 years ago.
Hi I am encountering a null pointer error when I click on the activity Links. The purpose of my feature is to call a list of links in the form of list view. Below is the logcat and as far as I understand it is coming from my onItemClickListener, but I can't seem to point out the null error.:
sitesList.setOnItemClickListener(new OnItemClickListener()
Links.java
package com.example.sgrecipe;
import java.io.FileNotFoundException;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
public class Links extends Activity {
private SitesAdapter mAdapter;
private ListView sitesList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.i("StackSites", "OnCreate()");
setContentView(R.layout.activity_main);
//Get reference to our ListView
sitesList = (ListView)findViewById(R.id.sitesList);
//Set the click listener to launch the browser when a row is clicked.
sitesList.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View v, int pos,long id) {
String url = mAdapter.getItem(pos).getLink();
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
});
/*
* If network is available download the xml from the Internet.
* If not then try to use the local file from last time.
*/
if(isNetworkAvailable()){
Log.i("StackSites", "starting download Task");
SitesDownloadTask download = new SitesDownloadTask();
download.execute();
}else{
mAdapter = new SitesAdapter(getApplicationContext(), -1, SitesXmlPullParser.getStackSitesFromFile(Links.this));
sitesList.setAdapter(mAdapter);
}
}
//Helper method to determine if Internet connection is available.
private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager
= (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}
/*
* AsyncTask that will download the xml file for us and store it locally.
* After the download is done we'll parse the local file.
*/
private class SitesDownloadTask extends AsyncTask<Void, Void, Void>{
#Override
protected Void doInBackground(Void... arg0) {
//Download the file
try {
Downloader.DownloadFromUrl("https://dl.dropboxusercontent.com/u/5724095/XmlParseExample/stacksites.xml", openFileOutput("StackSites.xml", Context.MODE_PRIVATE));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void result){
//setup our Adapter and set it to the ListView.
mAdapter = new SitesAdapter(Links.this, -1, SitesXmlPullParser.getStackSitesFromFile(Links.this));
sitesList.setAdapter(mAdapter);
Log.i("StackSites", "adapter size = "+ mAdapter.getCount());
}
}
}
activity_links.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Links" >
<ListView
android:id="#+id/sitesList"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
row_site.xml (for the listview)
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp" >
<ProgressBar
android:id="#+id/progress"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<ImageView
android:id="#+id/iconImg"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_marginRight="8dp" />
<TextView
android:id="#+id/nameTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/iconImg"
android:textSize="16sp"
android:textStyle="bold" />
<TextView
android:id="#+id/aboutTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="#id/iconImg"
android:textSize="12sp"
android:layout_below="#id/nameTxt"
/>
</RelativeLayout>
Here is the logcat:
02-23 15:13:10.856: E/AndroidRuntime(8201): FATAL EXCEPTION: main
02-23 15:13:10.856: E/AndroidRuntime(8201): Process: com.example.sgrecipe, PID: 8201
02-23 15:13:10.856: E/AndroidRuntime(8201): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sgrecipe/com.example.sgrecipe.Links}: java.lang.NullPointerException
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2292)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2350)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.app.ActivityThread.access$800(ActivityThread.java:163)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1257)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.os.Handler.dispatchMessage(Handler.java:102)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.os.Looper.loop(Looper.java:157)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.app.ActivityThread.main(ActivityThread.java:5335)
02-23 15:13:10.856: E/AndroidRuntime(8201): at java.lang.reflect.Method.invokeNative(Native Method)
02-23 15:13:10.856: E/AndroidRuntime(8201): at java.lang.reflect.Method.invoke(Method.java:515)
02-23 15:13:10.856: E/AndroidRuntime(8201): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
02-23 15:13:10.856: E/AndroidRuntime(8201): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
02-23 15:13:10.856: E/AndroidRuntime(8201): at dalvik.system.NativeStart.main(Native Method)
02-23 15:13:10.856: E/AndroidRuntime(8201): Caused by: java.lang.NullPointerException
02-23 15:13:10.856: E/AndroidRuntime(8201): at com.example.sgrecipe.Links.onCreate(Links.java:36)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.app.Activity.performCreate(Activity.java:5389)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
02-23 15:13:10.856: E/AndroidRuntime(8201): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2256)
Any help is really appreciate, thank you!

Change following line
setContentView(R.layout.activity_main);
to
setContentView(R.layout.activity_links);

Seems like your using different layouts:
setContentView(R.layout.activity_main);
vs
activity_links.xml

Unable to start activity ComponentInfo NullpointerException --

I wanted to make an app where you can make pictures and save them, but when I test it I got this error in my logcat: "java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.random/com.example.random.FotoMaker}: java.lang.NullPointerException". I think the problem has something to do with the intent, but im not sure what I need to add/change in my FotoMaker.java.
MenuScreen.java:
package com.example.random;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
public class MenuScreen extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
findViewById(R.id.test).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d("DEBUG", "test");
Intent intent = new Intent(MenuScreen.this, FotoMaker.class);
startActivityForResult(intent, 0);
}
});
findViewById(R.test1).setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Log.d("DEBUG", "test1");
Intent intent = new Intent(MenuScreen.this, FotoMaker.class);
}
});
findViewById(R.test2).setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Log.d("DEBUG", "test2");
Intent intent = new Intent(MenuScreen.this, FotoMaker.class);
}
});
findViewById(R.id.verlaat_app).setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Log.d("DEBUG", "test3");
MenuScreen.this.finish();
}
});
}
}
MenuScreen.java:
package com.example.random;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class FotoMaker extends Activity
{
ImageView iv;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.testpic);
iv = (ImageView) findViewById(R.id.imageView);
Button btn = (Button) findViewById(R.id.testpic);
btn.setOnClickListener(new OnClickListener()
{
#Override
public void onClick (View v){
Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, 0);
}
});
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
if(requestCode == 0)
{
Bitmap theImage = (Bitmap) data.getExtras().get("data");
iv.setImageBitmap(theImage);
}
}
}
LogCat:
11-16 18:30:14.366: E/AndroidRuntime(1522): FATAL EXCEPTION: main
11-16 18:30:14.366: E/AndroidRuntime(1522): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.random/com.example.random.FotoMaker}: java.lang.NullPointerException
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1996)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2023)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.app.ActivityThread.access$600(ActivityThread.java:127)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1174)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.os.Handler.dispatchMessage(Handler.java:99)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.os.Looper.loop(Looper.java:137)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.app.ActivityThread.main(ActivityThread.java:4503)
11-16 18:30:14.366: E/AndroidRuntime(1522): at java.lang.reflect.Method.invokeNative(Native Method)
11-16 18:30:14.366: E/AndroidRuntime(1522): at java.lang.reflect.Method.invoke(Method.java:511)
11-16 18:30:14.366: E/AndroidRuntime(1522): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
11-16 18:30:14.366: E/AndroidRuntime(1522): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
11-16 18:30:14.366: E/AndroidRuntime(1522): at dalvik.system.NativeStart.main(Native Method)
11-16 18:30:14.366: E/AndroidRuntime(1522): Caused by: java.lang.NullPointerException
11-16 18:30:14.366: E/AndroidRuntime(1522): at com.example.random.FotoMaker.onCreate(FotoMaker.java:27)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.app.Activity.performCreate(Activity.java:4479)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1050)
11-16 18:30:14.366: E/AndroidRuntime(1522): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1960)
11-16 18:30:14.366: E/AndroidRuntime(1522): ... 11 more
testpic.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="#drawable/ic_launcher" />
</LinearLayout>

It seems that you forget to add testpic button id in your xml layout,Therefore in FotoMaker activity your button btn is null.
Button btn = (Button) findViewById(R.id.testpic); <-- null here
So add button view with id testpic in your testpic.xml layout file.

Button btn = (Button) findViewById(R.id.testpic);
there is no Button called testpic in the layout "testpic"
you need to add a button testpic indide your layout file , otherwise it will return null.

android getViewById() NullPointerException

I'm trying to make my app changes its layout when user rotate the screen.
When i launch the app while the screen of virtual machines is in portrait position.
The app is ok when launch but when I rotate the screen to landscape, the app will stops and the logCat shows a nullPointerException at line 40
line 39 btn=(Button)findViewById(R.id.btn);
line 40 btn.setOnClickListener(btnListener);
I think the findViewById() method is returning null, but i dont know why.
Also, if i launch the app while screen in landscape position, the same error occured.
SOLVED: the problem might be the arrangement of nested if, add braces for every if and else-if do solve this problem
Here are the codes:
MainActivity.java
package com.example.test;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
SharedPreferences preference;
Button btn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
preference = getSharedPreferences("preferences", MODE_PRIVATE);
if(getResources().getConfiguration().orientation == 1)
if(preference.getInt("THE_CHECKED", 0) == 0)
setContentView(R.layout.portrait_black);
else if(preference.getInt("THE_CHECKED", 0) == 1)
setContentView(R.layout.portrait_white);
else if(getResources().getConfiguration().orientation == 2)
if(preference.getInt("THE_CHECKED", 0) == 0)
setContentView(R.layout.landscape_black);
else if(preference.getInt("THE_CHECKED", 0) == 1)
setContentView(R.layout.landscape_white);
btn=(Button)findViewById(R.id.btn);
btn.setOnClickListener(btnListener);
}
private Button.OnClickListener btnListener = new Button.OnClickListener()
{
public void onClick(View v)
{
Toast toast1 = Toast.makeText(MainActivity.this, "HI", Toast.LENGTH_LONG);
toast1.show();
}
};
private DialogInterface.OnClickListener theDialogListener = new DialogInterface.OnClickListener()
{
#Override
public void onClick(DialogInterface dialog, int which)
{
SharedPreferences.Editor editor = preference.edit();
switch(which)
{
case 0: //Black
editor.putInt("THE_CHECKED", 0);
break;
case 1: //White
editor.putInt("THE_CHECKED", 1);
break;
}
editor.commit();
((Dialog)dialog).dismiss();
onCreate(new Bundle());
}
};
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
SharedPreferences.Editor editor = preference.edit();
switch (item.getItemId())
{
case R.id.theme:
Builder theDialog = new AlertDialog.Builder(this);
theDialog.setTitle("Theme");
theDialog.setSingleChoiceItems(R.array.theme_menu, preference.getInt("THE_CHECKED", 0), theDialogListener);
theDialog.show();
break;
}
editor.commit();
return super.onOptionsItemSelected(item);
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
onCreate(new Bundle());
}
}
Layouts
portrait_white.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/LinearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
android:orientation="vertical" >
<Button
android:id="#+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="portrait"
android:textSize="30sp"
android:textColor="#000000" />
</LinearLayout>
portrait_black.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/LinearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000000"
android:orientation="vertical" >
<Button
android:id="#+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="portrait"
android:textSize="30sp"
android:textColor="#000000" />
</LinearLayout>
landscape_white.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/LinearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
android:orientation="vertical" >
<Button
android:id="#+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="landscape"
android:textSize="30sp"
android:textColor="#000000" />
</LinearLayout>
landscape_black.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/LinearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000000"
android:orientation="vertical" >
<Button
android:id="#+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="landscape"
android:textSize="30sp"
android:textColor="#000000" />
</LinearLayout>
LogCat(when i launch the app while screen is in landscape position)
02-21 01:26:53.895: D/AndroidRuntime(1836): Shutting down VM
02-21 01:26:53.925: W/dalvikvm(1836): threadid=1: thread exiting with uncaught exception (group=0x41465700)
02-21 01:26:53.935: E/AndroidRuntime(1836): FATAL EXCEPTION: main
02-21 01:26:53.935: E/AndroidRuntime(1836): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test/com.example.test.MainActivity}: java.lang.NullPointerException
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.app.ActivityThread.access$600(ActivityThread.java:141)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.os.Handler.dispatchMessage(Handler.java:99)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.os.Looper.loop(Looper.java:137)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.app.ActivityThread.main(ActivityThread.java:5103)
02-21 01:26:53.935: E/AndroidRuntime(1836): at java.lang.reflect.Method.invokeNative(Native Method)
02-21 01:26:53.935: E/AndroidRuntime(1836): at java.lang.reflect.Method.invoke(Method.java:525)
02-21 01:26:53.935: E/AndroidRuntime(1836): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
02-21 01:26:53.935: E/AndroidRuntime(1836): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
02-21 01:26:53.935: E/AndroidRuntime(1836): at dalvik.system.NativeStart.main(Native Method)
02-21 01:26:53.935: E/AndroidRuntime(1836): Caused by: java.lang.NullPointerException
02-21 01:26:53.935: E/AndroidRuntime(1836): at com.example.test.MainActivity.onCreate(MainActivity.java:40)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.app.Activity.performCreate(Activity.java:5133)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
02-21 01:26:53.935: E/AndroidRuntime(1836): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
02-21 01:26:53.935: E/AndroidRuntime(1836): ... 11 more
Thanks.

You don't have setContentView() in your Activity, hence, there's actually no View referenced to your activity and no views to find using findViewById() method, make sure the setContentView() was actually called...
Regards!

Use it this way. You have written nested if else and the second condition will never be executed in landscape mode i.e. orientation==2
package com.example.test;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
SharedPreferences preference;
Button btn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
preference = getSharedPreferences("preferences", MODE_PRIVATE);
if(getResources().getConfiguration().orientation == 1)
{
if(preference.getInt("THE_CHECKED", 0) == 0)
setContentView(R.layout.portrait_black);
else if(preference.getInt("THE_CHECKED", 0) == 1)
setContentView(R.layout.portrait_white);
}
else if(getResources().getConfiguration().orientation == 2)
if(preference.getInt("THE_CHECKED", 0) == 0)
setContentView(R.layout.landscape_black);
else if(preference.getInt("THE_CHECKED", 0) == 1)
setContentView(R.layout.landscape_white);
btn=(Button)findViewById(R.id.btn);
btn.setOnClickListener(btnListener);
}
private Button.OnClickListener btnListener = new Button.OnClickListener()
{
public void onClick(View v)
{
Toast toast1 = Toast.makeText(MainActivity.this, "HI", Toast.LENGTH_LONG);
toast1.show();
}
};
private DialogInterface.OnClickListener theDialogListener = new DialogInterface.OnClickListener()
{
#Override
public void onClick(DialogInterface dialog, int which)
{
SharedPreferences.Editor editor = preference.edit();
switch(which)
{
case 0: //Black
editor.putInt("THE_CHECKED", 0);
break;
case 1: //White
editor.putInt("THE_CHECKED", 1);
break;
}
editor.commit();
((Dialog)dialog).dismiss();
onCreate(new Bundle());
}
};
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
SharedPreferences.Editor editor = preference.edit();
switch (item.getItemId())
{
case R.id.theme:
Builder theDialog = new AlertDialog.Builder(this);
theDialog.setTitle("Theme");
theDialog.setSingleChoiceItems(R.array.theme_menu, preference.getInt("THE_CHECKED", 0), theDialogListener);
theDialog.show();
break;
}
editor.commit();
return super.onOptionsItemSelected(item);
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
onCreate(new Bundle());
}
}

Could you print the getResources().getConfiguration().orientation, I think it may be others values than 1 and 2
Infact, we have 4 value of getResources().getConfiguration().orientation: Configuration.ORIENTATION_PORTRAIT = 1, Configuration.ORIENTATION_LANDSCAPE =2, Configuration.ORIENTATION_SQUARE =3, Configuration.ORIENTATION_UNDEFINED =0

How do I make the back button I created in the activity change the text in the textView to the previous text created by the random generator?

When I start the activity on my phone, it says that the app is not responding. The problem is the back button which I can't seem to program to make it gather the previous text from the textView.
Xml code for activity
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/background"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".Author" >
<TextView
android:id="#+id/textView1"
android:layout_width="300dp"
android:layout_height="300dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:background="#drawable/button_shape"
android:text="#string/Getstarted"
android:textColor="#FFFFFF"
android:textSize="23sp" />
<ImageButton
android:id="#+id/next"
android:layout_width="90dp"
android:layout_height="50dp"
android:layout_alignRight="#+id/textView1"
android:layout_below="#+id/textView1"
android:layout_marginTop="14dp"
android:background="#drawable/button_shape"
android:contentDescription="#string/Next"
android:onClick="NextQuote"
android:src="#drawable/navigationnextitem" />
<ImageButton
android:id="#+id/share"
android:layout_width="90dp"
android:layout_height="50dp"
android:layout_alignTop="#+id/next"
android:layout_centerHorizontal="true"
android:background="#drawable/button_shape"
android:contentDescription="#string/share"
android:onClick="Sharing"
android:src="#drawable/socialshare" />
<ImageButton
android:id="#+id/back"
android:layout_width="90dp"
android:layout_height="50dp"
android:layout_alignLeft="#+id/textView1"
android:layout_alignTop="#+id/next"
android:background="#drawable/button_shape"
android:contentDescription="#string/Back"
android:onClick="PreviousQuote"
android:src="#drawable/navigationpreviousitem" />
</RelativeLayout>
Java code for activity
package com.android.motivateme3;
import java.util.Random;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.TextView;
import android.support.v4.app.NavUtils;
import android.annotation.TargetApi;
import android.content.Intent;
import android.os.Build;
public class Author extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_author);
// Show the Up button in the action bar.
setupActionBar();
}
/**
* Set up the {#link android.app.ActionBar}, if the API is available.
*/
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void setupActionBar() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getActionBar().setDisplayHomeAsUpEnabled(true);
Button NextQuote = (Button)findViewById(R.id.next);
final TextView display = (TextView) findViewById(R.id.textView1);
NextQuote.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
Random numGen = new Random();
int rNumber = numGen.nextInt(10);
if (rNumber == 0)
{
display.setText(R.string.Author1);
}
else if (rNumber == 1)
{
display.setText(R.string.Author2);
}
else if (rNumber == 2)
{
display.setText(R.string.Author3);
}
else if (rNumber == 3)
{
display.setText(R.string.Author4);
}
else if (rNumber == 4)
{
display.setText(R.string.Author5);
}
else if (rNumber == 5)
{
display.setText(R.string.Author6);
}
else if (rNumber == 6)
{
display.setText(R.string.Author7);
}
else if (rNumber == 7)
{
display.setText(R.string.Author8);
}
else if (rNumber == 8)
{
display.setText(R.string.Author9);
}
else if (rNumber == 9)
{
display.setText(R.string.Author10);
} }
});
}
ImageButton Sharing = (ImageButton)findViewById(R.id.share);
Sharing.setOnClickListener(new View.OnClickListener() {
public void onClick(View v){
TextView text = (TextView)findViewById(R.id.textView1);
String quote = text.getText().toString();{
Intent shareIntent = new Intent(android.content.Intent.ACTION_SEND);
shareIntent.setType("plain/text");
shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "This is a great quote (from the Motivate Me! app)");
shareIntent.putExtra(android.content.Intent.EXTRA_TEXT, quote);
startActivity(Intent.createChooser(shareIntent, "Share via:"));}}});
Button BackQuote = (Button)findViewById(R.id.back);
final TextView display = (TextView) findViewById(R.id.textView1);
BackQuote.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String prev = (String) display.getText();
display.setText(prev);
}
});}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.author, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// This ID represents the Home or Up button. In the case of this
// activity, the Up button is shown. Use NavUtils to allow users
// to navigate up one level in the application structure. For
// more details, see the Navigation pattern on Android Design:
//
// http://developer.android.com/design/patterns/navigation.html#up-vs-back
//
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
}
This is the stack trace
04-03 14:29:34.174: E/AndroidRuntime(17383): at android.app.ActivityThread.main(ActivityThread.java:4441)
04-03 14:29:34.174: E/AndroidRuntime(17383): at java.lang.reflect.Method.invokeNative(Native Method)
04-03 14:29:34.174: E/AndroidRuntime(17383): at java.lang.reflect.Method.invoke(Method.java:511)
04-03 14:29:34.174: E/AndroidRuntime(17383): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823)
04-03 14:29:34.174: E/AndroidRuntime(17383): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
04-03 14:29:34.174: E/AndroidRuntime(17383): at dalvik.system.NativeStart.main(Native Method)
04-03 14:29:34.174: E/AndroidRuntime(17383): Caused by: java.lang.ClassCastException: android.widget.ImageButton cannot be cast to android.widget.Button
04-03 14:29:34.174: E/AndroidRuntime(17383): at com.android.motivateme3.Author.setupActionBar(Author.java:36)
04-03 14:29:34.174: E/AndroidRuntime(17383): at com.android.motivateme3.Author.onCreate(Author.java:25)
04-03 14:29:34.174: E/AndroidRuntime(17383): at android.app.Activity.performCreate(Activity.java:4465)
04-03 14:29:34.174: E/AndroidRuntime(17383): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
04-03 14:29:34.174: E/AndroidRuntime(17383): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931)
04-03 14:29:34.174: E/AndroidRuntime(17383): ... 11 more
04-03 14:29:41.664: I/Process(17383): Sending signal. PID: 17383 SIG: 9

It seems to me that R.id.next refers to an ImageButton, which cannot be cast into a Button, since it is not a subclass of a Button
Do you happen to see a ClassCastException?
To fix that particular issue, replace:
Button NextQuote = (Button)findViewById(R.id.next);
with
ImageButton NextQuote = (ImageButton)findViewById(R.id.next);

My App works on Gingerbread... Crash on ICS and HC

I need your help.
My App works fine on GingerBread, but on ICS and HC crash.
This is the logcat
01-14 20:26:51.831: E/AndroidRuntime(698): FATAL EXCEPTION: main
01-14 20:26:51.831: E/AndroidRuntime(698): android.os.NetworkOnMainThreadException
01-14 20:26:51.831: E/AndroidRuntime(698): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
01-14 20:26:51.831: E/AndroidRuntime(698): at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
01-14 20:26:51.831: E/AndroidRuntime(698): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
01-14 20:26:51.831: E/AndroidRuntime(698): at java.net.InetAddress.getAllByName(InetAddress.java:220)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:71)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:351)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:86)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:308)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpEngine.connect(HttpEngine.java:303)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:282)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:232)
01-14 20:26:51.831: E/AndroidRuntime(698): at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:80)
01-14 20:26:51.831: E/AndroidRuntime(698): at com.bozz.milaircraft.f23$ImageAdapter.getView(f23.java:125)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.AbsSpinner.onMeasure(AbsSpinner.java:192)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1369)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.measureVertical(LinearLayout.java:660)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.onMeasure(LinearLayout.java:553)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.FrameLayout.onMeasure(FrameLayout.java:293)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1369)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.measureVertical(LinearLayout.java:660)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.onMeasure(LinearLayout.java:553)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.FrameLayout.onMeasure(FrameLayout.java:293)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1369)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.measureVertical(LinearLayout.java:660)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.onMeasure(LinearLayout.java:553)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.FrameLayout.onMeasure(FrameLayout.java:293)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.measureVertical(LinearLayout.java:812)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.LinearLayout.onMeasure(LinearLayout.java:553)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4698)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.widget.FrameLayout.onMeasure(FrameLayout.java:293)
01-14 20:26:51.831: E/AndroidRuntime(698): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2092)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.View.measure(View.java:12723)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1064)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2442)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.os.Handler.dispatchMessage(Handler.java:99)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.os.Looper.loop(Looper.java:137)
01-14 20:26:51.831: E/AndroidRuntime(698): at android.app.ActivityThread.main(ActivityThread.java:4424)
01-14 20:26:51.831: E/AndroidRuntime(698): at java.lang.reflect.Method.invokeNative(Native Method)
01-14 20:26:51.831: E/AndroidRuntime(698): at java.lang.reflect.Method.invoke(Method.java:511)
01-14 20:26:51.831: E/AndroidRuntime(698): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
01-14 20:26:51.831: E/AndroidRuntime(698): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
01-14 20:26:51.831: E/AndroidRuntime(698): at dalvik.system.NativeStart.main(Native Method)
Here is the layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:id="#+id/linearLayout3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#000"
android:paddingBottom="5dp"
android:paddingTop="5dp" >
<Button
android:id="#+id/homebutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:background="#drawable/homebutton" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="1"
android:gravity="center"
android:text="#string/nomeF22Raptor"
android:textColor="#FFD800"
android:textSize="22dp"
android:textStyle="bold" />
<Button
android:id="#+id/searchbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:background="#drawable/searchbutton" >
</Button>
</LinearLayout>
<TabHost
android:id="#+id/tabhost"
android:layout_width="match_parent"
android:layout_height="420dp"
android:layout_weight="0.80"
android:background="#drawable/background" >
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TabWidget
android:id="#android:id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</TabWidget>
<FrameLayout
android:id="#android:id/tabcontent"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:id="#+id/tab1"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ScrollView
android:id="#+id/ScrollView01"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="#+id/linearLayout2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/datiF22Raptor" />
</LinearLayout>
</ScrollView>
</LinearLayout>
<LinearLayout
android:id="#+id/tab2"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ScrollView
android:id="#+id/ScrollView01"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="#+id/linearLayout2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/cartecF22Raptor" />
</LinearLayout>
</ScrollView>
</LinearLayout>
<LinearLayout
android:id="#+id/tab3"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ScrollView
android:id="#+id/ScrollView01"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="#+id/linearLayout2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/utilizzatoriF22Raptor" />
</LinearLayout>
</ScrollView>
</LinearLayout>
<LinearLayout
android:id="#+id/tab4"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Gallery
android:id="#+id/gallery"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
<ImageView
android:id="#+id/ImageView01"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_gravity="center" >
</ImageView>
</LinearLayout>
</FrameLayout>
</LinearLayout>
</TabHost>
</LinearLayout>
and this is the java code
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.TabHost;
import android.widget.TabHost.TabSpec;
public class f23 extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.f23);
Button bhome = (Button) findViewById(R.id.homebutton);
bhome.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
startActivity(new Intent("com.bozz.milaircraft.MENU"));
}
});
TabHost th = (TabHost) findViewById(R.id.tabhost);
th.setup();
TabSpec specs = th.newTabSpec("tag1");
specs.setContent(R.id.tab1);
specs.setIndicator("BRIEFING");
th.addTab(specs);
specs = th.newTabSpec("tag2");
specs.setContent(R.id.tab2);
specs.setIndicator("DESIGN");
th.addTab(specs);
specs = th.newTabSpec("tag3");
specs.setContent(R.id.tab3);
specs.setIndicator("USERS");
th.addTab(specs);
specs = th.newTabSpec("tag4");
specs.setContent(R.id.tab4);
specs.setIndicator("GALLERY");
th.addTab(specs);
Gallery ga = (Gallery) findViewById(R.id.gallery);
ga.setAdapter(new ImageAdapter(this));
}
public class ImageAdapter extends BaseAdapter {
/** The parent context */
private Context myContext;
int imageBackground;
/** URL-Strings to some remote images. */
private String[] myRemoteImages = {
"http://www.medicinarozzano.it/images/milair/f4_1.jpg",
"http://www.medicinarozzano.it/images/milair/f4_2.jpg",
"http://www.medicinarozzano.it/images/milair/f4_3.jpg",
"http://www.medicinarozzano.it/images/milair/f4_4.jpg",
"http://www.medicinarozzano.it/images/milair/f4_5.jpg",
"http://www.medicinarozzano.it/images/milair/f4_6.jpg",
"http://www.medicinarozzano.it/images/milair/f4_7.jpg",
"http://www.medicinarozzano.it/images/milair/f4_8.jpg",
"http://www.medicinarozzano.it/images/milair/f4_9.jpg",
"http://www.medicinarozzano.it/images/milair/f4_10.jpg"};
/** Simple Constructor saving the 'parent' context. */
public ImageAdapter(Context c) {
this.myContext = c;
}
/** Returns the amount of images we have defined. */
public int getCount() {
return this.myRemoteImages.length;
}
/* Use the array-Positions as unique IDs */
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
/**
* Returns a new ImageView to be displayed, depending on the position
* passed.
*/
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(this.myContext);
try {
/* Open a new URL and get the InputStream to load data from it. */
URL aURL = new URL(myRemoteImages[position]);
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
/* Buffered is always good for a performance plus. */
BufferedInputStream bis = new BufferedInputStream(is);
/* Decode url-data to a bitmap. */
Bitmap bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
/* Apply the Bitmap to the ImageView that will be returned. */
i.setImageBitmap(bm);
} catch (IOException e) {
i.setImageResource(R.drawable.f4_1);
Log.e("DEBUGTAG", "Remote Image Exception", e);
}
/* Image should be scaled as width/height are set. */
i.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
/* Set the Width/Height of the ImageView. */
i.setLayoutParams(new Gallery.LayoutParams(480, 640));
return i;
}
/**
* Returns the size (0.0f to 1.0f) of the views depending on the
* 'offset' to the center.
*/
public float getScale(boolean focused, int offset) {
/* Formula: 1 / (2 ^ offset) */
return Math.max(0, 1.0f / (float) Math.pow(2, Math.abs(offset)));
}
}
}
The App crash when I click on the Gallery Tab.

It is a bad idea to perform (potentially blocking) network operations on your app's main thread, which is what you are doing. Before Honeycomb (Android 3.0), it was just a bad idea. From Android 3.0 onwards, it is prohibited, and you receive this exception if you try to do so.
See http://developer.android.com/reference/android/os/NetworkOnMainThreadException.html
You need to farm out this network logic to a separate asynchronous thread. Or, look at a Handler. You're going to need to change your code architecture; no easy fix.

In Honeycomb networking is not allowed on the UI thread. The reason is that it slows down the user interface (UI).
Instead try to download your images in an background thread, the easiest way to implement this is using an AsyncTask.

Use it at your own risk:
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll()
.build();
StrictMode.setThreadPolicy(policy);
Resource:
http://developer.android.com/reference/android/os/StrictMode.ThreadPolicy.Builder.html

You can see the version of the OS, and execute a code depending of it.
For example:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD)

This is how I solve the problem:
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.entity.BufferedHttpEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.TabHost;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.TabHost.TabSpec;
public class f24 extends Activity {
private ImageAdapter imageAdapter;
private ArrayList<String> PhotoURLS = new ArrayList<String>();
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.f24);
Button bhome = (Button) findViewById(R.id.homebutton);
bhome.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
startActivity(new Intent ("com.bozz.milaircraft.MENU"));
}
});
TabHost th = (TabHost) findViewById(R.id.tabhost);
th.setup();
TabSpec specs = th.newTabSpec("tag1");
specs.setContent(R.id.tab1);
specs.setIndicator("BRIEFING");
th.addTab(specs);
specs = th.newTabSpec("tag2");
specs.setContent(R.id.tab2);
specs.setIndicator("DESIGN");
th.addTab(specs);
specs = th.newTabSpec("tag3");
specs.setContent(R.id.tab3);
specs.setIndicator("USERS");
th.addTab(specs);
specs = th.newTabSpec("tag4");
specs.setContent(R.id.tab4);
specs.setIndicator("GALLERY");
th.addTab(specs);
imageAdapter = new ImageAdapter(this);
final ImageView imgView = (ImageView) findViewById(R.id.GalleryView);
Gallery g = (Gallery) findViewById(R.id.Gallery);
g.setAdapter(imageAdapter);
g.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
imgView.setImageDrawable(LoadImageFromURL(PhotoURLS
.get(position)));
imgView.setScaleType(ImageView.ScaleType.FIT_CENTER);
}
});
// replace this code to set your image urls in list
PhotoURLS.add("http://www.medicinarozzano.it/images/milair/f4_1.jpg");
PhotoURLS.add("http://www.medicinarozzano.it/images/milair/f4_1.jpg");
new AddImageTask().execute();
}
class AddImageTask extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... unused) {
for (String url : PhotoURLS) {
String filename = url.substring(url.lastIndexOf("/") + 1,
url.length());
filename = "th_" + filename;
String thumburl = url.substring(0, url.lastIndexOf("/") + 1);
imageAdapter.addItem(LoadThumbnailFromURL(thumburl + filename));
publishProgress();
//SystemClock.sleep(200);
}
return (null);
}
#Override
protected void onProgressUpdate(Void... unused) {
imageAdapter.notifyDataSetChanged();
}
#Override
protected void onPostExecute(Void unused) {
}
}
private Drawable LoadThumbnailFromURL(String url) {
try {
URLConnection connection = new URL(url).openConnection();
String contentType = connection.getHeaderField("Content-Type");
boolean isImage = contentType.startsWith("image/");
if(isImage){
HttpGet httpRequest = new HttpGet(url);
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = (HttpResponse) httpclient
.execute(httpRequest);
HttpEntity entity = response.getEntity();
BufferedHttpEntity bufferedHttpEntity = new BufferedHttpEntity(entity);
InputStream is = bufferedHttpEntity.getContent();
Drawable d = Drawable.createFromStream(is, "src Name");
return d;
} else {
Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.no_image);
Drawable d = new BitmapDrawable(b);
return d;
}
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Error", Toast.LENGTH_LONG)
.show();
Log.e(e.getClass().getName(), e.getMessage(), e);
return null;
}
}
private Drawable LoadImageFromURL(String url) {
try {
URLConnection connection = new URL(url).openConnection();
String contentType = connection.getHeaderField("Content-Type");
boolean isImage = contentType.startsWith("image/");
if(isImage){
HttpGet httpRequest = new HttpGet(url);
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = (HttpResponse) httpclient
.execute(httpRequest);
HttpEntity entity = response.getEntity();
BufferedHttpEntity bufferedHttpEntity = new BufferedHttpEntity(
entity);
InputStream is = bufferedHttpEntity.getContent();
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(is, null, o);
// The new size we want to scale to
final int REQUIRED_SIZE = 150;
// Find the correct scale value. It should be the power of 2.
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// Decode with inSampleSize
is = bufferedHttpEntity.getContent();
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
Bitmap b = BitmapFactory.decodeStream(is, null, o2);
Drawable d = new BitmapDrawable(b);
return d;
} else {
Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.no_image);
Drawable d = new BitmapDrawable(b);
return d;
}
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Error", Toast.LENGTH_LONG)
.show();
Log.e(e.getClass().getName(), e.getMessage(), e);
return null;
}
}
public class ImageAdapter extends BaseAdapter {
int mGalleryItemBackground;
private Context mContext;
ArrayList<Drawable> drawablesFromUrl = new ArrayList<Drawable>();
public ImageAdapter(Context c) {
mContext = c;
TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);
mGalleryItemBackground = a.getResourceId(
R.styleable.Gallery1_android_galleryItemBackground, 0);
a.recycle();
}
public void addItem(Drawable item) {
drawablesFromUrl.add(item);
}
public int getCount() {
return drawablesFromUrl.size();
}
public Drawable getItem(int position) {
return drawablesFromUrl.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(mContext);
i.setImageDrawable(drawablesFromUrl.get(position));
i.setLayoutParams(new Gallery.LayoutParams(150, 120));
i.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
i.setBackgroundResource(mGalleryItemBackground);
return i;
}
}
}
But now I have another problem:
If i don not declare any SDK on Android Manifest, the app works perfectly on both gingerbread and HC, and ICS. However, if i declare a minimum SDK greater than 1 or TargetSDK, the app works fine on gingerbread but not on HC and ISC. When i click on an image in the gallery nothing appears on the image viewer. Yet, a toast error pops up.
Also, if there is no internet connection the app crashes.
Best regards
Tiberio Bozotti
EDIT:
i could remove the SDK but on honeycomb it is not clear. Meaning that the layout is not compatible.