的Android的ImageButton點擊

我在我的活動有一點點問題在我的佈局的Android的ImageButton點擊

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" android:layout_width="fill_parent" 
    android:layout_height="fill_parent" android:weightSum="1"> 

    <ImageButton android:id="@+id/startLogo" 
    android:layout_height="230dp" 
    android:adjustViewBounds="true" 
    android:background="@drawable/whatelsecomics" 
    android:layout_width="230dp" 
    android:layout_gravity="center_horizontal"/> 

</LinearLayout>

我

public class WhatelsecomicsActivity extends Activity { 

    private ImageButton whatelsecomics; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); // your layout file name 

     whatelsecomics = (ImageButton) findViewById(R.id.startLogo); // your image button 

    // click event on your button 
    whatelsecomics.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      Intent wecSeriesList = new Intent(WhatelsecomicsActivity.this, wecSeriesListActivity.class); 
      //Start next activity 
      WhatelsecomicsActivity.this.startActivity(wecSeriesList); 
     } 
    }); 
}

在我的日誌

}

09-23 21:31:05.081: ERROR/AndroidRuntime(3805): FATAL EXCEPTION: main 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805): java.lang.RuntimeException: Unable to start activity ComponentInfo{zepod.whatelsecomics/zepod.whatelsecomics.WhatelsecomicsActivity}: java.lang.NullPointerException 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.os.Handler.dispatchMessage(Handler.java:99) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.os.Looper.loop(Looper.java:123) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.app.ActivityThread.main(ActivityThread.java:3683) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at java.lang.reflect.Method.invokeNative(Native Method) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at java.lang.reflect.Method.invoke(Method.java:507) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at dalvik.system.NativeStart.main(Native Method) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805): Caused by: java.lang.NullPointerException 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at zepod.whatelsecomics.WhatelsecomicsActivity.onCreate(WhatelsecomicsActivity.java:21) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 
09-23 21:31:05.081: ERROR/AndroidRuntime(3805):  ... 11 more

任何人都可以說我爲什麼？

來源

2011-09-23 aczepod

如果您使用Eclipse，請單擊Project->Clean...（如果您沒有自動執行此操作，請重新構建它）。像這樣的問題的通常原因是R文件沒有正確生成，因此重新生成項目以再次生成它。

來源

2011-09-23 21:45:25 DeeV

謝謝，這是正確的方法;） – aczepod

你有NullPointerException異常上WhatelsecomicsActivity.java:21

什麼線是什麼？

來源

2011-09-23 21:36:18

whatelsecomics.setOnClickListener（new View.OnClickListener（）{ – aczepod

OK，然後findViewById（）沒有返回一個按鈕。確保你引用了一個視圖，並在R中定義了R.id.startLogo。 layout.main。 –

是的，我是ImageButton android：id =「@ + id/startLogo」和findViewById（R.id.startLogo） – aczepod

的Android的ImageButton點擊

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