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Error in Fragment Activity in Android

I am trying a fragment app as per a tutorial and getting following error:
06-28 04:21:47.118: D/AndroidRuntime(1491): Shutting down VM
06-28 04:21:47.128: W/dalvikvm(1491): threadid=1: thread exiting with uncaught exception (group=0xb4af7b90)
06-28 04:21:47.158: E/AndroidRuntime(1491): FATAL EXCEPTION: main
06-28 04:21:47.158: E/AndroidRuntime(1491): Process: com.example.fragmentapp, PID: 1491
06-28 04:21:47.158: E/AndroidRuntime(1491): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.fragmentapp/com.example.fragmentapp.MainActivity}: android.view.InflateException: Binary XML file line #8: Error inflating class fragment
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2176)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.ActivityThread.access$700(ActivityThread.java:135)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.os.Handler.dispatchMessage(Handler.java:102)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.os.Looper.loop(Looper.java:137)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.ActivityThread.main(ActivityThread.java:4998)
06-28 04:21:47.158: E/AndroidRuntime(1491): at java.lang.reflect.Method.invokeNative(Native Method)
06-28 04:21:47.158: E/AndroidRuntime(1491): at java.lang.reflect.Method.invoke(Method.java:515)
06-28 04:21:47.158: E/AndroidRuntime(1491): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
06-28 04:21:47.158: E/AndroidRuntime(1491): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
06-28 04:21:47.158: E/AndroidRuntime(1491): at dalvik.system.NativeStart.main(Native Method)
06-28 04:21:47.158: E/AndroidRuntime(1491): Caused by: android.view.InflateException: Binary XML file line #8: Error inflating class fragment
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:713)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
06-28 04:21:47.158: E/AndroidRuntime(1491): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:290)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.Activity.setContentView(Activity.java:1928)
06-28 04:21:47.158: E/AndroidRuntime(1491): at com.example.fragmentapp.MainActivity.onCreate(MainActivity.java:13)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.Activity.performCreate(Activity.java:5243)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140)
06-28 04:21:47.158: E/AndroidRuntime(1491): ... 11 more
06-28 04:21:47.158: E/AndroidRuntime(1491): Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.pavan.fragmentdemo.MyListFragment: make sure class name exists, is public, and has an empty constructor that is public
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.Fragment.instantiate(Fragment.java:597)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.Fragment.instantiate(Fragment.java:561)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.Activity.onCreateView(Activity.java:4777)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:689)
06-28 04:21:47.158: E/AndroidRuntime(1491): ... 21 more
06-28 04:21:47.158: E/AndroidRuntime(1491): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.pavan.fragmentdemo.MyListFragment" on path: DexPathList[[zip file "/data/app/com.example.fragmentapp-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.fragmentapp-2, /system/lib]]
06-28 04:21:47.158: E/AndroidRuntime(1491): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
06-28 04:21:47.158: E/AndroidRuntime(1491): at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
06-28 04:21:47.158: E/AndroidRuntime(1491): at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
06-28 04:21:47.158: E/AndroidRuntime(1491): at android.app.Fragment.instantiate(Fragment.java:583)
06-28 04:21:47.158: E/AndroidRuntime(1491): ... 24 more
The code is as follows:
Main Activity.java
package com.example.fragmentapp;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
public class MainActivity extends Activity implements
ListFragment.Communicator {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public void Message(String OS_Name) {
DetailFragment detailfragment = (DetailFragment) getFragmentManager()
.findFragmentById(R.id.detail_Fragment);
if (detailfragment != null && detailfragment.isInLayout()) {
detailfragment.setText(OS_Name);
}
else {
Intent intent = new Intent(getApplicationContext(),
DetailActivity.class);
Bundle extras = new Bundle();
extras.putString(DetailActivity.os_name, OS_Name);
intent.putExtras(extras);
startActivity(intent);
}
}
}
Code of DetailActivity.java
package com.example.fragmentapp;
import android.app.Activity;
import android.content.res.Configuration;
import android.os.Bundle;
public class DetailActivity extends Activity {
public static String os_name = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
finish();
return;
}
setContentView(R.layout.detail_activity);
Bundle extras = getIntent().getExtras();
if (extras != null) {
String name = extras.getString(os_name);
DetailFragment detailFragment = (DetailFragment) getFragmentManager()
.findFragmentById(R.id.detailFragment);
detailFragment.setText(name);
}
}
}
Code of DetailFragment.java
package com.example.fragmentapp;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class DetailFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.detail_fragment, container, false);
return view;
}
// we call this method when button from listfragment is clicked
public void setText(String item) {
TextView view = (TextView) getView().findViewById(R.id.display_tv);
view.setText(item);
}
}
Code of ListFragment.java
package com.example.fragmentapp;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
public class ListFragment extends Fragment implements OnClickListener {
private Communicator communicator;
Button android_btn, ios_btn, windows_btn;
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
if (activity instanceof Communicator) {
communicator = (Communicator) activity;
}
else {
throw new
ClassCastException(activity.toString()
+ " must implemenet MyListFragment.Communicator");
}
}
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
View view =
inflater.inflate(R.layout.list_fragment, container, false);
// Initialize Views android_btn = (Button)
view.findViewById(R.id.android_btn_id);
ios_btn = (Button)
view.findViewById(R.id.ios_btn_id);
windows_btn = (Button)
view.findViewById(R.id.windows_btn_id);
// set on click Listeners for buttons
android_btn.setOnClickListener(this);
ios_btn.setOnClickListener(this);
windows_btn.setOnClickListener(this);
return view;
}
//Create Interface
public interface Communicator {
public void Message(String OS_Name);
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.android_btn_id:
updateFragment("Android");
break;
case R.id.ios_btn_id:
updateFragment("IOS");
break;
case R.id.windows_btn_id:
updateFragment("Windows");
break;
}
}
private void updateFragment(String OS_Name) {
communicator.Message(OS_Name);
}
}
In Layout Folder
activity_main.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="horizontal" >
<fragment
android:id="#+id/list_Fragment"
android:layout_width="0sp"
android:layout_height="match_parent"
android:layout_weight="1"
class="com.pavan.fragmentdemo.MyListFragment" >
</fragment>
<fragment
android:id="#+id/detail_Fragment"
android:layout_width="0sp"
android:layout_height="match_parent"
android:layout_weight="2"
class="com.pavan.fragmentdemo.DetailFragment" >
</fragment>
</LinearLayout>
Code of detail_fragment.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:background="#FFFF99"
android:orientation="vertical"
android:padding="20dp" >
<TextView
android:id="#+id/display_tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=""
android:textSize="40sp" />
</LinearLayout>
code of list_fragment.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:background="#CCFF99"
android:orientation="vertical"
android:padding="5dp" >
<Button
android:id="#+id/android_btn_id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Android" />
<Button
android:id="#+id/ios_btn_id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="IOS" />
<Button
android:id="#+id/windows_btn_id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Windows" />
</LinearLayout>
In layout-port
code activity_main.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" >
<fragment
android:id="#+id/list_Fragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
class="com.pavan.fragmentdemo.MyListFragment" >
</fragment>
</LinearLayout>
Code of detail_activity.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" >
<fragment
android:id="#+id/detailFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.pavan.fragmentdemo.DetailFragment" />
</LinearLayout>

You have different names of fragments:
in xml com.pavan.fragmentdemo.MyListFragment
in java com.example.fragmentapp.MyListFragment
fix package names

.com.process stopped unexpectedly in Android emulator and mobile

I am trying to make a simple android app that will add two numbers and display the output.However, I am getting the following error continuously.
"calculator.com.process stopped unexpectedly"
I used API 10 for rendering layout and API 17 as compiler and Target SDK.
Could post the code finally after all these trouble.
This is the code of main_activity.java
package com.example.calculator;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
EditText txtNum1;
EditText txtNum2;
TextView Display;
Button bCal;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txtNum1=(EditText) findViewById(R.id.Num1);
txtNum1=(EditText) findViewById(R.id.Num2);
Display=(TextView)findViewById(R.id.tvDisplay);
bCal=(Button)findViewById(R.id.bAdd);
bCal.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View Tawfiq) {
// TODO Auto-generated method stub
double x=Double.parseDouble(txtNum1.getText().toString());
double y=Double.parseDouble(txtNum2.getText().toString());
double total=x+y;
Display.setText("Sum is"+total);
}
});
}
#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);
}
}
The xml code:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/bAdd"
android:layout_width="match_parent"
android:layout_height="match_parent"
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="com.example.calculator.MainActivity" >
<EditText
android:id="#+id/Num1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="50dp"
android:ems="10"
android:inputType="numberDecimal" >
<requestFocus />
</EditText>
<EditText
android:id="#+id/Num2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/Num1"
android:layout_below="#+id/Num1"
android:layout_marginTop="33dp"
android:ems="10"
android:inputType="numberDecimal" />
<Button
android:id="#+id/bAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/tvDisplay"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp"
android:text="Button" />
<TextView
android:id="#+id/tvDisplay"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/Num2"
android:layout_centerHorizontal="true"
android:layout_marginTop="30dp"
android:text="Sum"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
This is the logcat.
01-24 16:06:39.840: D/AndroidRuntime(1130): Shutting down VM
01-24 16:06:39.870: W/dalvikvm(1130): threadid=1: thread exiting with uncaught exception (group=0xb60164f0)
01-24 16:06:39.950: E/AndroidRuntime(1130): FATAL EXCEPTION: main
01-24 16:06:39.950: E/AndroidRuntime(1130): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.calculator/com.example.calculator.MainActivity}: java.lang.ClassCastException: android.widget.RelativeLayout
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.os.Handler.dispatchMessage(Handler.java:99)
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.os.Looper.loop(Looper.java:130)
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.app.ActivityThread.main(ActivityThread.java:3683)
01-24 16:06:39.950: E/AndroidRuntime(1130): at java.lang.reflect.Method.invokeNative(Native Method)
01-24 16:06:39.950: E/AndroidRuntime(1130): at java.lang.reflect.Method.invoke(Method.java:507)
01-24 16:06:39.950: E/AndroidRuntime(1130): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-24 16:06:39.950: E/AndroidRuntime(1130): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-24 16:06:39.950: E/AndroidRuntime(1130): at dalvik.system.NativeStart.main(Native Method)
01-24 16:06:39.950: E/AndroidRuntime(1130): Caused by: java.lang.ClassCastException: android.widget.RelativeLayout
01-24 16:06:39.950: E/AndroidRuntime(1130): at com.example.calculator.MainActivity.onCreate(MainActivity.java:27)
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-24 16:06:39.950: E/AndroidRuntime(1130): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
01-24 16:06:39.950: E/AndroidRuntime(1130): ... 11 more

You are having problem at line no-27
Caused by: java.lang.ClassCastException: android.widget.RelativeLayout
01-24 16:06:39.950: E/AndroidRuntime(1130): at com.example.calculator.MainActivity.onCreate(MainActivity.java:27)
Change the relativeLayouts Id in the xml file.
It should not be same as for the add button.
android:id="#+id/relativeLayout"
Change it as above.
Two id in the same layout cannot be same.
Your add button and the relative layout is having the same id,.
And during the findViewById(), relative layout is being caste in the Button.
That's why class cast exception is coming.
Edit:
I compiled your code:-
the next mistake you have made is-
txtNum1=(EditText) findViewById(R.id.Num2);
It should be
txtNum2=(EditText) findViewById(R.id.Num2);
Mistake-You are not assigning the reference to the second edittext.

NoSaveStateFrameLayout cannot be cast to android.widget.TableLayout

I can't start my android application. I'm using TableLayout in fragment_main.xml. And I think that problem somewhere in using it in code.
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/main_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
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="com.nikolay.calculator.MainActivity$PlaceholderFragment" >
<TableRow
android:id="#+id/tableRow1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<EditText
android:id="#+id/firstNum"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="7"
android:hint="#string/hint1"
android:inputType="number|text" >
</EditText>
//....
<TableRow
android:id="#+id/tableRow5"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<TextView
android:id="#+id/textResult"
android:gravity="center"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/textResult"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="#+id/result"
android:gravity="center"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/result"
android:textAppearance="?android:attr/textAppearanceLarge" />
</TableRow>
</TableLayout>
Here is my MainActivity class. In initWidget() method I set onclicklistener for all buttons and set my EditText and TextView fields. onCreate method was created by eclipse. I just added two last strings. Give only a piece of code.
public class MainActivity extends ActionBarActivity implements View.OnClickListener {
private CalcJavaLayer javaCalc;
private double a;
private double b;
private TableLayout table;
private EditText firstNum;
private EditText secondNum;
private TextView result;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
javaCalc = new CalcJavaLayer();
initWidgets();
}
private void initWidgets(){
table = (TableLayout) findViewById(R.id.main_fragment);
for(int i = 0; i < table.getChildCount(); i++){
TableRow row = (TableRow) table.getChildAt(i);
for(int j = 0; j < row.getChildCount(); j++){
if(row.getChildAt(j) instanceof Button){
Button button = (Button) row.getChildAt(j);
button.setOnClickListener(this);
}else if(row.getChildAt(j) instanceof EditText){
firstNum = (EditText) row.getChildAt(0);
secondNum = (EditText) row.getChildAt(1);
break;
}else if(row.getChildAt(j) instanceof TextView){
result = (TextView) row.getChildAt(1);
break;
}
}
}
}
And I receive next errors
05-20 14:45:35.649: E/AndroidRuntime(1701): FATAL EXCEPTION: main
05-20 14:45:35.649: E/AndroidRuntime(1701): Process: com.nikolay.calculator, PID: 1701
05-20 14:45:35.649: E/AndroidRuntime(1701): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.nikolay.calculator/com.nikolay.calculator.MainActivity}: java.lang.ClassCastException: android.support.v4.app.NoSaveStateFrameLayout cannot be cast to android.widget.TableLayout
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.os.Handler.dispatchMessage(Handler.java:102)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.os.Looper.loop(Looper.java:136)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.app.ActivityThread.main(ActivityThread.java:5017)
05-20 14:45:35.649: E/AndroidRuntime(1701): at java.lang.reflect.Method.invokeNative(Native Method)
05-20 14:45:35.649: E/AndroidRuntime(1701): at java.lang.reflect.Method.invoke(Method.java:515)
05-20 14:45:35.649: E/AndroidRuntime(1701): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-20 14:45:35.649: E/AndroidRuntime(1701): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-20 14:45:35.649: E/AndroidRuntime(1701): at dalvik.system.NativeStart.main(Native Method)
05-20 14:45:35.649: E/AndroidRuntime(1701): Caused by: java.lang.ClassCastException: android.support.v4.app.NoSaveStateFrameLayout cannot be cast to android.widget.TableLayout
05-20 14:45:35.649: E/AndroidRuntime(1701): at com.nikolay.calculator.MainActivity.initWidgets(MainActivity.java:91)
05-20 14:45:35.649: E/AndroidRuntime(1701): at com.nikolay.calculator.MainActivity.onCreate(MainActivity.java:46)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.app.Activity.performCreate(Activity.java:5231)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
05-20 14:45:35.649: E/AndroidRuntime(1701): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
05-20 14:45:35.649: E/AndroidRuntime(1701): ... 11 more
searches in google have not yielded results. Appreciate any help!

Android app crash on startup

I really don't know whats wrong with this...
The app should only change the text of the text view when clicking a button, in this case the start button.
When I start the app with the virtual machine it crashes.
My code
package com.example.projectiii;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
Button btnS = (Button) findViewById(R.id.btStart);
btnS.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View view) {
// TODO Auto-generated method stub
TextView word = (TextView) findViewById(R.id.display);
word.setText("Project");
}
});
}
#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);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
}
My 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"
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="com.example.projectiii.MainActivity$PlaceholderFragment" >
<EditText
android:id="#+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/display"
android:layout_centerHorizontal="true"
android:layout_marginTop="46dp"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="#+id/btStart"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/text"
android:layout_below="#+id/text"
android:layout_marginTop="42dp"
android:text="Start" />
<Button
android:id="#+id/btFinish"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/btStart"
android:layout_alignRight="#+id/text"
android:text="Finish" />
<Chronometer
android:id="#+id/time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_alignRight="#+id/text"
android:layout_marginTop="40dp"
android:text="Chronometer" />
<TextView
android:id="#+id/display"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/time"
android:layout_centerHorizontal="true"
android:layout_marginTop="66dp"
android:text="Text"
android:textSize="30sp" />
My logcat
05-03 15:06:48.720: E/AndroidRuntime(921): FATAL EXCEPTION: main
05-03 15:06:48.720: E/AndroidRuntime(921): Process: com.example.projectiii, PID: 921
05-03 15:06:48.720: E/AndroidRuntime(921): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.projectiii/com.example.projectiii.MainActivity}: java.lang.NullPointerException
05-03 15:06:48.720: E/AndroidRuntime(921): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.os.Handler.dispatchMessage(Handler.java:102)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.os.Looper.loop(Looper.java:136)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.app.ActivityThread.main(ActivityThread.java:5017)
05-03 15:06:48.720: E/AndroidRuntime(921): at java.lang.reflect.Method.invokeNative(Native Method)
05-03 15:06:48.720: E/AndroidRuntime(921): at java.lang.reflect.Method.invoke(Method.java:515)
05-03 15:06:48.720: E/AndroidRuntime(921): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-03 15:06:48.720: E/AndroidRuntime(921): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-03 15:06:48.720: E/AndroidRuntime(921): at dalvik.system.NativeStart.main(Native Method)
05-03 15:06:48.720: E/AndroidRuntime(921): Caused by: java.lang.NullPointerException
05-03 15:06:48.720: E/AndroidRuntime(921): at com.example.projectiii.MainActivity.onCreate(MainActivity.java:33)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.app.Activity.performCreate(Activity.java:5231)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
05-03 15:06:48.720: E/AndroidRuntime(921): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
05-03 15:06:48.720: E/AndroidRuntime(921): ... 11 more
05-03 15:06:48.760: W/ActivityManager(385): Force finishing activity com.example.projectiii/.MainActivity

Make sure the xml you posted is activity_main, not fragment_main. You don't need a Fragment here, so remove all Fragment-related code.

Bind the view of TextView here:
setContentView(R.layout.activity_main);
TextView word = (TextView) findViewById(R.id.display);

the layout xml you have shown is of the fragment(since it doesn't contain the R.id. container). You are trying to access the button element defined in your Fragment layout in your activity which is giving you he null pointer. Try accessing the button from the fragment class which will resolve your error.

The application has stopped unexpectedly . Error-caused by: Java.lang.NullPointerException

main.java
package com.learnactivities;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class Main extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity);
Button b = (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(Main.this, Second.class));
}
});
}
}
activity.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"
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=".Main" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button1" />
</RelativeLayout>
Second.java
package com.learnactivities;
import android.app.Activity;
import android.os.Bundle;
public class Second extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
}
}
second.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"
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=".Second" >
<TextView
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="16dp"
android:layout_marginTop="15dp"
android:text="#string/nd" />
</RelativeLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.learnactivities"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.learnactivities.Main"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".second" />
</application>
</manifest>
I m getting following errors. I can see that error caused by java.lang.NullPointerException. I did my best searching here and there but could not get to the solution.Plz, anyone help me sort this problem out?
08-25 19:08:44.442: D/AndroidRuntime(276): Shutting down VM
08-25 19:08:44.442: W/dalvikvm(276): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
08-25 19:08:44.472: E/AndroidRuntime(276): FATAL EXCEPTION: main
08-25 19:08:44.472: E/AndroidRuntime(276): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.learnactivities/com.learnactivities.Main}: java.lang.NullPointerException
08-25 19:08:44.472: E/AndroidRuntime(276): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
08-25 19:08:44.472: E/AndroidRuntime(276): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
08-25 19:08:44.472: E/AndroidRuntime(276): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
08-25 19:08:44.472: E/AndroidRuntime(276): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
08-25 19:08:44.472: E/AndroidRuntime(276): at android.os.Handler.dispatchMessage(Handler.java:99)
08-25 19:08:44.472: E/AndroidRuntime(276): at android.os.Looper.loop(Looper.java:123)
08-25 19:08:44.472: E/AndroidRuntime(276): at android.app.ActivityThread.main(ActivityThread.java:4627)
08-25 19:08:44.472: E/AndroidRuntime(276): at java.lang.reflect.Method.invokeNative(Native Method)
08-25 19:08:44.472: E/AndroidRuntime(276): at java.lang.reflect.Method.invoke(Method.java:521)
08-25 19:08:44.472: E/AndroidRuntime(276): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-25 19:08:44.472: E/AndroidRuntime(276): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-25 19:08:44.472: E/AndroidRuntime(276): at dalvik.system.NativeStart.main(Native Method)
08-25 19:08:44.472: E/AndroidRuntime(276): Caused by: java.lang.NullPointerException
08-25 19:08:44.472: E/AndroidRuntime(276): at com.learnactivities.Main.onCreate(Main.java:19)
08-25 19:08:44.472: E/AndroidRuntime(276): at `android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)`
`08-25 19:08:44.472: E/AndroidRuntime(276): at` `android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)`
08-25 19:08:44.472: E/AndroidRuntime(276): ... 11 more

R.id.button1 is declared inside second.xml, but you are looking for it inside activity.xml. So in Main, when you do
Button b = (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener()
findViewById is returning null

Try this in your main class..
TextView b = (TextView ) findViewById(R.id.textView1);
b.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(Main.this, Second.class));
}
});
and also in manifest change like below line
<activity android:name=".Second" />