unfortunately app has stopped button object

Question

I have this problem even when I use other class like Edit Text.

I am sure about the id.

This is the code:

public class MainActivity extends ActionBarActivity 
{
    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button bshow = (Button)findViewById(R.id.show_msg);

        bshow.setText("Showing");
    }

}

this is the fragment_main.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.exampleknight283.e003.MainActivity$PlaceholderFragment" >

   <TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/hello_world" />

   <Button
    android:id="@+id/show_msg"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/textView1"
    android:layout_marginTop="44dp"
    android:text="@string/showv" />

    </RelativeLayout>

and i got this on logout

  07-16 11:27:32.155: E/Trace(1382): error opening trace file: No such file or      directory (2)
  07-16 11:27:32.625: D/AndroidRuntime(1382): Shutting down VM
  07-16 11:27:32.625: W/dalvikvm(1382): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
  07-16 11:27:32.645: E/AndroidRuntime(1382): FATAL EXCEPTION: main
  07-16 11:27:32.645: E/AndroidRuntime(1382): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.exampleknight283.e003/com.exampleknight283.e003.MainActivity}: java.lang.NullPointerException
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.os.Handler.dispatchMessage(Handler.java:99)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.os.Looper.loop(Looper.java:137)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.app.ActivityThread.main(ActivityThread.java:5041)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at java.lang.reflect.Method.invokeNative(Native Method)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at java.lang.reflect.Method.invoke(Method.java:511)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
  07-16 11:27:32.645: E/AndroidRuntime(1382):   at dalvik.system.NativeStart.main(Native Method)
  07-16 11:27:32.645: E/AndroidRuntime(1382): Caused by: java.lang.NullPointerException
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at com.exampleknight283.e003.MainActivity.onCreate(MainActivity.java:29)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.app.Activity.performCreate(Activity.java:5104)
 07-16 11:27:32.645: E/AndroidRuntime(1382):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
  07-16 11:27:32.645: E/AndroidRuntime(1382):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)

I am new in android dev. but i am good in java and now i follow some Tutorials i did exastly what he did but i have the error and like what i said i have same problem with other classes like "Edit Class"

possible duplicate of [Unfortunately MyApp has stopped. How can I solve this?](http://stackoverflow.com/questions/23353173/unfortunately-myapp-has-stopped-how-can-i-solve-this) — panini, Jul 16 '14 at 00:34
Is it just a typo or did you inflate the wrong layout? (You show the content of `fragment_main.xml`, yet you inflate `R.layout.activity_main`) — stealthjong, Jul 16 '14 at 12:25

score 0 · Answer 1 · answered Jul 16 '14 at 01:49

0

Try:

public class MainActivity extends ActionBarActivity 
{
    Button bshow;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        bshow = (Button) findViewById(R.id.show_msg);

        bshow.setText("Showing");
    }

}

answered Jul 16 '14 at 01:49

SQLiteNoob

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yes stealthjong you are right it is about activity_main i did not set for that , because i am new in android dev. thanks – Senior Knight Jul 16 '14 at 14:33

unfortunately app has stopped button object

1 Answers1