java.lang.RuntimeException：無法啓動活動ComponentInfo

現在我已經搜索了幾個小時來查找代碼中的失敗。我在我的代碼中得到了NPE。java.lang.RuntimeException：無法啓動活動ComponentInfo

這是ImageButton和setOnClickListener的東西。

這裏的堆棧跟蹤：

04-01 23:37:43.912: W/asset(6416):  Copying FileAsset 0x77cecd20 (zip:/data/app/net.test.apk:/resources.arsc) to buffer size 7000 to make it aligned. 
04-01 23:37:43.962: W/dalvikvm(6416):  threadid=1: thread exiting with uncaught exception (group=0x416736f8) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  FATAL EXCEPTION: main 
04-01 23:37:43.972: E/AndroidRuntime(6416):  Process: net.test, PID: 6416 
04-01 23:37:43.972: E/AndroidRuntime(6416): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.test/net.test.MainActivity}: java.lang.NullPointerException 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.app.ActivityThread.access$800(ActivityThread.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.os.Handler.dispatchMessage(Handler.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.os.Looper.loop(Looper.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.app.ActivityThread.main(ActivityThread.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at java.lang.reflect.Method.invokeNative(Native Method) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at java.lang.reflect.Method.invoke(Method.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at dalvik.system.NativeStart.main(Native Method) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  Caused by: java.lang.NullPointerException 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at net.test.MainActivity.onCreate(MainActivity.java:24) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.app.Activity.performCreate(Activity.java) 
04-01 23:37:43.972: E/AndroidRuntime(6416):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java)

這裏的.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:background="@drawable/main_back" 
android:gravity="center_horizontal" 
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="net.ringmybuddy.MainActivity$PlaceholderFragment" > 

<ImageView 
    android:id="@+id/imageView1" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="140dp" 
    android:contentDescription="@string/button_step1" 
    android:src="@drawable/start_image_step1" /> 

<ImageView 
    android:id="@+id/imageView2" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignLeft="@+id/imageView1" 
    android:layout_below="@+id/imageView1" 
    android:contentDescription="@string/button_step2" 
    android:src="@drawable/start_image_step2" /> 

<ImageView 
    android:id="@+id/imageView3" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignLeft="@+id/imageView2" 
    android:layout_below="@+id/imageView2" 
    android:contentDescription="@string/button_step3" 
    android:src="@drawable/start_image_step3" /> 

<ImageView 
    android:id="@+id/imageView4" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignLeft="@+id/imageView3" 
    android:layout_below="@+id/imageView3" 
    android:layout_marginTop="40dp" 
    android:contentDescription="@string/start_rmb_schriftzug" 
    android:src="@drawable/start_rmb_schriftzug" /> 

<ImageButton 
    android:id="@+id/einrichten" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_below="@+id/imageView4" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="0dp" 
    android:contentDescription="@string/button_einrichten" 
    android:src="@drawable/start_button_einrichten" /> 

<TextView 
    android:id="@+id/textView2" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_marginTop="55dp" 
    android:gravity="center_horizontal" 
    android:text="@string/startroutine_einleitung" 
    android:textAppearance="?android:attr/textAppearanceMedium" 
    android:textColor="#ffffff" 
    android:textSize="15sp" 
    android:textStyle="normal" 
    android:typeface="normal" /> 

<ImageView 
    android:id="@+id/imageView5" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignBottom="@+id/newtest" 
    android:layout_marginBottom="17dp" 
    android:layout_marginLeft="11dp" 
    android:layout_toRightOf="@+id/newtest" 
    android:contentDescription="@string/pfeil_2arrows" 
    android:src="@drawable/start_image_arrows" /> 

<TextView 
    android:id="@+id/textView3" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentBottom="true" 
    android:layout_centerHorizontal="true" 
    android:layout_marginBottom="0dp" 
    android:text="@string/copyright" 
    android:textAppearance="?android:attr/textAppearanceMedium" 
    android:textColor="#bcb081" 
    android:textSize="12sp" /> 

<TextView 
    android:id="@+id/textView1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:layout_centerHorizontal="true" 
    android:layout_marginTop="-5dp" 
    android:text="@string/startroutine_ueberschrift" 
    android:textAppearance="?android:attr/textAppearanceMedium" 
    android:textColor="#ffffff" 
    android:textSize="18sp" 
    android:textStyle="bold" 
    android:typeface="normal" /> 

</RelativeLayout>

在MainActivity：

package net.test; 

import android.app.Activity; 
import android.app.Fragment; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ImageButton; 

public class MainActivity extends Activity implements View.OnClickListener{ 

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


    ImageButton einrichten = (ImageButton)findViewById(R.id.einrichten); 

    einrichten.setOnClickListener(new View.OnClickListener(){ 

      public void onClick(View v) { 
       Intent in = new Intent 
         (
           MainActivity.this, 
           EinstellungenMainActivityOn.class 

         ); 

       startActivity(in); 
       } 

    }); 

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


@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; 
    } 
} 

@Override 
public void onClick(View v) { 
    // TODO Auto-generated method stub 

} 

}

是啊，我知道這是在MainActivity，但我的第24行不知道如何解決這個問題。我已經嘗試了一切，沒有爲我工作。我希望你們夥計們能幫助我。非常感謝提前！

編輯：對不起，我忘了添加MainActivity。

來源

2014-04-01 user3487010

什麼是線24 @'MainActivity '？我想你忘了發佈'MainActivity'代碼 –

你能發佈MainActivity代碼嗎？ – JavierSP1209

你沒有einrichten ID在activity_main，這xml您發佈對我們來說是你的片段是fragment_main，所以你必須有一個ImageButton的與einrichten ID在activity_main或處理點擊片段類。

我寫的代碼改變片段爲您，

讓你在片段代碼必須是：

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
     Bundle savedInstanceState) { 
    View rootView = inflater.inflate(R.layout.fragment_main, container, false); 

    ImageButton einrichten = (ImageButton)rootView.findViewById(R.id.einrichten); 

    einrichten.setOnClickListener(new View.OnClickListener(){ 

     public void onClick(View v) { 
      Intent in = new Intent 
        (
          getActivity(), 
          EinstellungenMainActivityOn.class 

        ); 

      startActivity(in); 
      } 

}); 

    return rootView; 
}

，並在MainActivity：

@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(); 
    } 
}

來源

2014-04-01 22:14:52

謝謝！我是這樣一個傻瓜包。 ^^ – user3487010

java.lang.RuntimeException：無法啓動活動ComponentInfo

回答

相關問題