Google Android - это несложно

04-25 17:28:32.307: D/AndroidRuntime(21161): Shutting down VM
04-25 17:28:32.307: W/dalvikvm(21161): threadid=1: thread exiting with uncaught exception (group=0x40d0a930)
04-25 17:28:32.317: E/AndroidRuntime(21161): FATAL EXCEPTION: main
04-25 17:28:32.317: E/AndroidRuntime(21161): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rrrr/com.example.rrrr.MainActivity}: java.lang.NullPointerException
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.app.ActivityThread.access$600(ActivityThread.java:141)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.os.Handler.dispatchMessage(Handler.java:99)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.os.Looper.loop(Looper.java:137)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.app.ActivityThread.main(ActivityThread.java:5039)
04-25 17:28:32.317: E/AndroidRuntime(21161): at java.lang.reflect.Method.invokeNative(Native Method)
04-25 17:28:32.317: E/AndroidRuntime(21161): at java.lang.reflect.Method.invoke(Method.java:511)
04-25 17:28:32.317: E/AndroidRuntime(21161): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-25 17:28:32.317: E/AndroidRuntime(21161): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-25 17:28:32.317: E/AndroidRuntime(21161): at dalvik.system.NativeStart.main(Native Method)
04-25 17:28:32.317: E/AndroidRuntime(21161): Caused by: java.lang.NullPointerException
04-25 17:28:32.317: E/AndroidRuntime(21161): at com.example.rrrr.MainActivity.onCreate(MainActivity.java:31)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.app.Activity.performCreate(Activity.java:5104)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
04-25 17:28:32.317: E/AndroidRuntime(21161): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
04-25 17:28:32.317: E/AndroidRuntime(21161): ... 11 more

adarash писал(а):может код покажешь?

package com.example.rrrr;

import android.app.Activity;
import android.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;

public class MainActivity extends Activity {

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

if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}


final TextView txt = (TextView) findViewById(R.id.txt);
Button btn = (Button) findViewById(R.id.btn);

btn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
txt.setText(213123);
}
});

}

@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;
}
}

}

adarash писал(а):Вот в чем дело. Когда: "Button btn = (Button) findViewById(R.id.btn);" он не находит btn и поэтому он null. А вешать на null слушатель приводит к вылету. Проверь. И еще можешь Project -> Clean.. Тоже иногда эклипс глючит.

<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.rrrr.MainActivity$PlaceholderFragment" >

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

<Button
android:id="@+id/btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/txt"
android:layout_marginLeft="14dp"
android:layout_marginTop="87dp"
android:layout_toRightOf="@+id/txt"
android:text="@string/textBtn" />

</RelativeLayout>

Foenix писал(а):Alex2014
перейди по ссылке в подписи.