OnClickListener NullPoinerException錯誤？

我試圖清理我的監聽器，並弄錯了一些東西：我在LogCat w /下面的方法中得到了一個典型的'NullPoinerException'（第一次嘗試這樣做）。OnClickListener NullPoinerException錯誤？

任何幫助？日Thnx！

的活動：

public class List_RegulatoryDocs extends Activity { 

OnClickListener myClickListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     if (v == acItem) { 
      Intent ACList = new Intent(List_RegulatoryDocs.this, 
        List_AC.class); 
      startActivity(ACList); 
     } else if (v == adItem) { 
      // TODO 
     }else if (v == cfrItem) { 
      // TODO 
     }//TODO + items 
    } 
}; 

/** 
* -- Called when the activity is first created 
* =================================================================== 
*/ 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    setContentView(R.layout.regulatory_docs_list); 

    // Set the Click Listeners 
    acItem.setOnClickListener(myClickListener); 
    adItem.setOnClickListener(myClickListener); 
    cfrItem.setOnClickListener(myClickListener); 

} 

/** 
* -- Local Variables 
* ===================================================================== 
**/ 
RelativeLayout acItem = (RelativeLayout) findViewById(R.id.acItem); 
RelativeLayout adItem = (RelativeLayout) findViewById(R.id.adItem); 
RelativeLayout cfrItem = (RelativeLayout) findViewById(R.id.cfrItem); 
// RelativeLayout pmaItem = (RelativeLayout) findViewById(R.id.pmaItem); 
// RelativeLayout saibItem = (RelativeLayout) findViewById(R.id.saibItem); 
// RelativeLayout sfarItem = (RelativeLayout) findViewById(R.id.sfarItem); 
// RelativeLayout stcItem = (RelativeLayout) findViewById(R.id.stcItem); 
// RelativeLayout tsoItem = (RelativeLayout) findViewById(R.id.tsoItem); 
// RelativeLayout tcdsItem = (RelativeLayout) findViewById(R.id.tcdsItem); 
}

的logcat：

05-05 01:27:29.931: WARN/dalvikvm(13268): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): FATAL EXCEPTION: main 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.aeroTechnologies.flyDroid/com.aeroTechnologies.flyDroid.regList.List_RegulatoryDocs}: java.lang.NullPointerException 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.app.ActivityThread.access$2300(ActivityThread.java:125) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.os.Handler.dispatchMessage(Handler.java:99) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.os.Looper.loop(Looper.java:123) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.app.ActivityThread.main(ActivityThread.java:4627) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at java.lang.reflect.Method.invokeNative(Native Method) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at java.lang.reflect.Method.invoke(Method.java:521) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at dalvik.system.NativeStart.main(Native Method) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268): Caused by: java.lang.NullPointerException 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.app.Activity.findViewById(Activity.java:1637) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at com.aeroTechnologies.flyDroid.regList.List_RegulatoryDocs.<init>(List_RegulatoryDocs.java:51) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at java.lang.Class.newInstanceImpl(Native Method) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at java.lang.Class.newInstance(Class.java:1429) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.app.Instrumentation.newActivity(Instrumentation.java:1021) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577) 
05-05 01:27:29.971: ERROR/AndroidRuntime(13268):  ... 11 more

來源

2011-05-05 CelticParser

恩，這是一個典型的NPE？（提示：發佈LogCat） – kcoppock 2011-05-05 01:21:55

@kcoppock嗨，添加了LogCat。 – CelticParser 2011-05-05 01:31:48

jk和Ted差不多。您應該在onCreate內或在其他視圖的上下文中進行分配。當您嘗試分配RelativeLayouts時，您的NPE正在發生。 – kcoppock 2011-05-05 01:41:16

聲明acItem，adItem，cfrItem（如果你喜歡成員變量）然後在onCreate（）;

public class List_RegulatoryDocs extends Activity { 
RelativeLayout acItem ; 
RelativeLayout adItem; 
RelativeLayout cfrItem ; 
OnClickListener myClickListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     if (v == acItem) { 
      Intent ACList = new Intent(List_RegulatoryDocs.this, 
        List_AC.class); 
      startActivity(ACList); 
     } else if (v == adItem) { 
      // TODO 
     }else if (v == cfrItem) { 
      // TODO 
     }//TODO + items 
    } 
}; 

/** 
* -- Called when the activity is first created 
* =================================================================== 
*/ 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    setContentView(R.layout.regulatory_docs_list); 
acItem = (RelativeLayout) findViewById(R.id.acItem); 
adItem = (RelativeLayout) findViewById(R.id.adItem); 
cfrItem = (RelativeLayout) findViewById(R.id.cfrItem); 
    // Set the Click Listeners 
    acItem.setOnClickListener(myClickListener); 
    adItem.setOnClickListener(myClickListener); 
    cfrItem.setOnClickListener(myClickListener); 

} 

/** 
* -- Local Variables 
* ===================================================================== 
**/ 

// RelativeLayout pmaItem = (RelativeLayout) findViewById(R.id.pmaItem); 
// RelativeLayout saibItem = (RelativeLayout) findViewById(R.id.saibItem); 
// RelativeLayout sfarItem = (RelativeLayout) findViewById(R.id.sfarItem); 
// RelativeLayout stcItem = (RelativeLayout) findViewById(R.id.stcItem); 
// RelativeLayout tsoItem = (RelativeLayout) findViewById(R.id.tsoItem); 
// RelativeLayout tcdsItem = (RelativeLayout) findViewById(R.id.tcdsItem); 
}

來源

2011-05-05 01:31:03 jkhouw1

Thnx！這有助於學習新東西。 – CelticParser 2011-05-05 14:15:07

在onCreate，你似乎訪問acItem，adItem，並沒有cfrItem初始化它們。

來源

2011-05-05 01:27:19

OnClickListener NullPoinerException錯誤？

回答

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