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Android thread test does not work

Hi I'm beginner with android development and I have a problem with my following test code:
Main Activity:
package com.test.thread;
import java.util.concurrent.ExecutionException;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
TextView txt = null;
Button btStart = null;
Button btStop = null;
TestClass test = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txt = (TextView)findViewById(R.id.txtView);
btStart = (Button)findViewById(R.id.bt_start);
btStop = (Button)findViewById(R.id.bt_stop);
test = new TestClass(this, txt);
btStop.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
test.Stop();
}
});
btStart.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Thread t = new Thread(){
#Override
public void run() {
// TODO Auto-generated method stub
try{
synchronized (this) {
wait(50);
runOnUiThread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
while(test.isStop()){
try {
wait(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
test.DoSomeThing();
}
}
});
}
}catch( InterruptedException e)
{
e.printStackTrace();
}
}
};
t.start();
}
});
}
#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) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
TestCLas.java:
package com.tutorial.sample;
import android.content.Context;
import android.widget.TextView;
import android.widget.Toast;
public class TestClass{
private boolean stopIter = false;
private TextView txtV = null;
private int count = 0;
private Context ctx = null;
public TestClass(Context ct, TextView tv) {
// TODO Auto-generated constructor stub
txtV = tv;
stopIter = false;
count = 0;
ctx = ct;
}
public boolean isStop() { return stopIter; }
public void Stop()
{
Toast.makeText(ctx, "stop the test" , Toast.LENGTH_LONG).show();
count = 0;
txtV.setText(Integer.toString(count));
stopIter = true;
}
public void DoSomeThing(){
txtV.setText(Integer.toString(count));
}
}
I want to manage my activity's viewer with threads. I launch a thread in order to modify TextView's text (each sec) when the start button is clicked and stop it when stop button is clicked. But it does not work, it crashes without any exception. Can someone help me please?

wait(1000);
This should NEVER be done on the UI thread.
The UI thread is the one that update the GUI, and communicates with Android to say everything is working as expected. When you have a thread delay on the UI thread, the message to and from the android system get held back, and you app appears to the system as if it has crashed.

android activity work with intent

i made three activities for a game i want to go from 1st to 2nd to 3rd and then go 1st 2nd 3rd again but i got confused with the whole intent thing tried all kind of combinations but for some reason i stuck always with a problem currently it goes from 1st to 2nd to 3rd to 1st and when it supposed to lunch 2nd it exits from the whole app
//1st activity
Intent discoverintent = new Intent(getBaseContext(), discoverstring.class);
//discoverintent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(discoverintent);
//2nd activity
Intent MainIntent = new Intent(getBaseContext(), learningword.class);
//MainIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
MainIntent.putExtra("text", text);
MainIntent.putExtra("speakeronoff", Integer.toString(speakeronoff));
MainIntent.putExtra("previous", Integer.toString(previous));
startActivity(MainIntent);
and the 3rd activity just uses finish
package self.yanfaingold.talkgame;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.Window;
import android.view.WindowManager;
#SuppressLint("NewApi") public class savewords extends Activity implements OnTouchListener {
OurView v;
//Intent secondintent;
Canvas c;
int cheight,cwidth,loop=0;
Bitmap notalk,notalkscaled,bittalk;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
v=new OurView(this);
v.setOnTouchListener(this);
//Remove title bar
requestWindowFeature(Window.FEATURE_NO_TITLE);
//Remove notification bar
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(v);
notalk=BitmapFactory.decodeResource(getResources(), R.drawable.nottalk);
// bittalk=BitmapFactory.decodeResource(getResources(), R.drawable.talkmid);
}
#Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
v.pause();
}
#Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
v.resume();
}
public class OurView extends SurfaceView implements Runnable {
Thread t=null;
SurfaceHolder holder;
boolean isItOK=false;
public OurView(Context context) {
super(context);
// TODO Auto-generated constructor stub
holder=getHolder();
}
public void run(){
while(isItOK){
if(!holder.getSurface().isValid()){
continue;
}
c=holder.lockCanvas();
cheight=c.getHeight();
cwidth=c.getWidth();
scale();
drawing(c);
holder.unlockCanvasAndPost(c);
}
}
private void scale() {
// TODO Auto-generated method stub
if(loop==0)
notalkscaled=Bitmap.createScaledBitmap(notalk,(int)(cwidth),(int)(cheight), false);
}
protected void drawing(Canvas canvas){
//canvas.drawARGB(255, 255, 255, 255);
canvas.drawBitmap(notalkscaled,0,0, null);
if(loop>500){
loop=0;
wannalearnaword();
}
loop++;
}
private void wannalearnaword() {
// TODO Auto-generated method stub
//1st activity
Intent secondintent = new Intent(getApplicationContext(), discoverstring.class);
secondintent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(secondintent);
}
public void pause(){
isItOK=false;
while(true){
try {
t.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
}
t=null;
}
public void resume(){
isItOK=true;
t=new Thread(this);
t.start();
}
}
#Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
switch(event.getAction())
{
case MotionEvent.ACTION_DOWN:
break;
case MotionEvent.ACTION_UP:
break;
case MotionEvent.ACTION_MOVE:
break;
}
return true;
}
}

how to display alert dialog box in button if target action fails

I am trying to create an app where the user can take a photo and set it as wallpaper.Now when i click the button and get back without taking a photo and click set wallpaper i want to display an alert dialog box.I have been able to set it when the image capture is not initiated but not when initiated but no image is taken
package com.sagarapp;
import java.io.IOException;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
public class Camera extends Activity implements View.OnClickListener{
ImageView img;
ImageButton takepic;
Button setdp;
Intent i;
final static int cameraData = 0;
Bitmap bmp;
final Context context = this;
boolean taken = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.photo);
initialize();
takepic.setOnClickListener(this);
setdp.setOnClickListener(this);
}
private void initialize() {
// TODO Auto-generated method stub
img = (ImageView)findViewById(R.id.Ivpic);
takepic = (ImageButton)findViewById(R.id.Ibcapture);
setdp = (Button)findViewById(R.id.Bsetdp);
}
#SuppressWarnings("deprecation")
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch(v.getId())
{
case R.id.Ibcapture:
i = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
taken = true;
startActivityForResult(i,cameraData);
break;
case R.id.Bsetdp:
try {
if(taken)
getApplicationContext().setWallpaper(bmp);
else{
AlertDialog.Builder alertDialogBulider = new AlerDialog.Builder(context);
alertDialogBulider.setTitle("Warning!");
alertDialogBulider.setMessage("No Image Is Available");
alertDialogBulider.setCancelable(false);
alertDialogBulider.setNeutralButton("OK", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int id) {
// TODO Auto-generated method stub
dialog.cancel();
}
});
AlertDialog alertDialog = alertDialogBulider.create();
alertDialog.show();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK)
{
Bundle extras = data.getExtras();
bmp = (Bitmap)extras.get("data");
img.setImageBitmap(bmp);
}
else
{
AlertDialog.Builder alertDialogBulider = new AlertDialog.Builder(context);
alertDialogBulider.setTitle("Warning!");
alertDialogBulider.setMessage("No Photo Is Taken");
alertDialogBulider.setCancelable(false);
alertDialogBulider.setNeutralButton("OK", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int id) {
// TODO Auto-generated method stub
dialog.cancel();
}
});
AlertDialog alertDialog = alertDialogBulider.create();
alertDialog.show();
}
}
}

Your taken boolean variable should only be set to true if you receive a RESULT_OK resultcode in onActivityResult() method. That means that the user actually took a picture and saved it. Remove it from the R.id.Ibcapture View onClick () method.

Button and menus stop working after orientation change

I have an Android app which uses tabs and fragments for navigation. The app works fine when launched, but after I change the orientation the menu items and the widgets in the fragments stop working. The app works if I put
android:configChanges="orientation|screenSize"
in the manifest, but in the Android documentation it says that this should be a last resort, so I'm wondering if there is a better solution. Here's the code for the host activity and one of the fragments.
package com.mynews;
import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.Menu;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main);
//stopService(new Intent(this, FindArticlesService.class));
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
Tab tab = actionBar.newTab()
.setText("Articles")
.setTabListener(new TabListener<Articles>(this, "articles", Articles.class));
actionBar.addTab(tab);
tab = actionBar.newTab()
.setText("Websites")
.setTabListener(new TabListener<UserSites>(this, "websites", UserSites.class));
actionBar.addTab(tab);
tab = actionBar.newTab()
.setText("Add a website")
.setTabListener(new TabListener<AddSites>(this, "add a site", AddSites.class));
actionBar.addTab(tab);
}
#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
protected void onSaveInstanceState(Bundle outState) {
// TODO Auto-generated method stub
super.onSaveInstanceState(outState);
}
#Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
////Intent intent = new Intent(this, FindArticlesService.class);
//this.startService(intent);
}
public static class TabListener<T extends Fragment> implements ActionBar.TabListener {
Fragment fragment;
final Activity activity;
final String tag;
final Class<T> mClass;
public TabListener(Activity a, String s, Class<T> c){
activity = a;
tag = s;
mClass = c;
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
if(fragment == null){
fragment = Fragment.instantiate(activity, mClass.getName());
ft.add(android.R.id.content, fragment, tag);
}else{
ft.attach(fragment);
}
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
if(fragment != null){
ft.detach(fragment);
}
activity.closeContextMenu();
}
}
}
My Fragment Class
package com.mynews;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.MalformedURLException;
import java.util.ArrayList;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class AddSites extends Fragment {
public AddSites(){}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_add_sites);
// Show the Up button in the action bar.
setHasOptionsMenu(true);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onActivityCreated(savedInstanceState);
Button button = (Button) getActivity().findViewById(R.id.add);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
UserSitesFunc usf = new UserSitesFunc(); //create a new UserSitesFunc to hold
try{ //the list of sites
FileInputStream fis = getActivity().openFileInput("MySites.ser");//check if there's a file
ObjectInputStream ois = new ObjectInputStream(fis);//with a USF object
usf = (UserSitesFunc) ois.readObject(); //if there is, deserialize it and use it
ois.close();//instead of a brand new object
}catch(IOException e){ //catch various exceptions
e.printStackTrace();
}catch(Exception ep){
ep.printStackTrace();
}finally{
try{ //do this with either the new object or the deserialised one
EditText website = (EditText) getActivity().findViewById(R.id.editText1);//get the input
EditText keywords = (EditText) getActivity().findViewById(R.id.editText2);//from the user
String web = website.getText().toString(); //store it in strings
String key = keywords.getText().toString();
String[] kwords = key.split(", ");
ArrayList<String> newKeywords = new ArrayList<String>();
for(String s:kwords){
newKeywords.add(s);
}
Sites s = new Sites(web, newKeywords);//create a new site from the input
if(usf.siteList.contains(s)){
showContainedDialog();
return;
}
usf.addSite(s);//add it to the user's list of sites
FileOutputStream fs = getActivity().openFileOutput("MySites.ser", Context.MODE_PRIVATE);//save it
ObjectOutputStream oos = new ObjectOutputStream(fs);
oos.writeObject(usf);
oos.close();
Toast.makeText(getActivity(), web + " added to Tracked Websites", Toast.LENGTH_LONG).show();
website.setText("");
keywords.setText("");
}catch(MalformedURLException mue){
showDialog();
}catch(Exception ex){
ex.printStackTrace();
}
}
}
});
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View view = inflater.inflate(R.layout.activity_add_sites, container, false);
return view;
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
menu.clear();
inflater.inflate(R.menu.add_sites, menu);
super.onCreateOptionsMenu(menu, inflater);
}
#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
//
return true;
}
return super.onOptionsItemSelected(item);
}
public static class NotAWebsiteDialog extends DialogFragment {
public static NotAWebsiteDialog newInstance(){
NotAWebsiteDialog notAWebsite = new NotAWebsiteDialog();
Bundle args = new Bundle();
notAWebsite.setArguments(args);
return notAWebsite;
}
#Override
public Dialog onCreateDialog(final Bundle savedInstanceState) {
// TODO Auto-generated method stub
return new AlertDialog.Builder(getActivity())
.setMessage("Please enter a vaild web address")
.create();
}
}
public void showDialog(){
DialogFragment dialog = NotAWebsiteDialog.newInstance();
dialog.show(getFragmentManager(), "Not A Website");
}
public static class AlreadyContainsWebsiteDialog extends DialogFragment {
public static AlreadyContainsWebsiteDialog newInstance(){
AlreadyContainsWebsiteDialog containsAWebsite = new AlreadyContainsWebsiteDialog();
Bundle args = new Bundle();
containsAWebsite.setArguments(args);
return containsAWebsite;
}
#Override
public Dialog onCreateDialog(final Bundle savedInstanceState) {
// TODO Auto-generated method stub
return new AlertDialog.Builder(getActivity())
.setMessage("This website is already being tracked")
.create();
}
}
public void showContainedDialog(){
DialogFragment dialog = AlreadyContainsWebsiteDialog.newInstance();
dialog.show(getFragmentManager(), "Contains this Website");
}
}

Kudos for not taking the easy way... keep up your programming efforts!
Refer to my answer here regarding the use of Menus and their host Fragments.

Intent is not working on click event

Hy experts.
i am new to android, i am trying to generate an intent to go on next activity, i am using listview, when i click on list item, it should go to that class which item item is clicked.
here is my code.
package com.example.data_server_assi;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class Menu extends ListActivity{
String[] menu = {"AddInfo","DataBaseInfo"};
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setListAdapter(new ArrayAdapter<String>(Menu.this, android.R.layout.simple_list_item_1, menu));
}
#Override
protected void onListItemClick(ListView l, View v, int position, long id) {
// TODO Auto-generated method stub
super.onListItemClick(l, v, position, id);
try {
Toast.makeText(Menu.this, "Test" ,Toast.LENGTH_SHORT).show();
Class menuItem = Class.forName("com.example.data_server_assi."+menu[position]);
Intent menuIntent = new Intent(Menu.this,menuItem);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}`

Put below code, You have missed one line of code:
Intent menuIntent = new Intent(Menu.this,menuItem);
startActivity(menuIntent);
OR
startActivity(new Intent(menu.this,menuItem));

You have missed starting your activity by-
startActivity(YOUR_INTENT_NAME);