列表視圖的NullPointerException內onCreateDialogView

我試着去創建一個對話框，它的工作原理只是當我嘗試添加該部分的ListView列表視圖的NullPointerException內onCreateDialogView

protected View onCreateDialogView() { 
    LayoutInflater inflater = ((SettingsActivity) ctx).getLayoutInflater(); 
    View vw = inflater.inflate(R.layout.channel_content_view, null); 
    ListView lv = (ListView) vw.findViewById(android.R.id.list); 
    Log.i("DIALOG", lv.toString()); ---- **RIGHT HERE IT BREAKS at com.example.tvrplayer.ChannelsDialogPreference.onCreateDialogView(ChannelsDialogPreference.java:56)** 
    return vw; 
}

如果我刪除列表視圖位，它的工作原理，並顯示空對話框。

channel_content_view.xml

<LinearLayout 
    android:id="@+id/channels_list" 
    android:layout_height="fill_parent"  
    android:layout_width="fill_parent" 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="horizontal">  

</LinearLayout>

堆棧跟蹤

02-28 13:37:15.768: E/AndroidRuntime(24732): FATAL EXCEPTION: main 
02-28 13:37:15.768: E/AndroidRuntime(24732): java.lang.NullPointerException 
02-28 13:37:15.768: E/AndroidRuntime(24732): at com.example.tvrplayer.ChannelsDialogPreference.onCreateDialogView(ChannelsDialogPreference.java:56) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.preference.DialogPreference.showDialog(DialogPreference.java:285) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.preference.DialogPreference.onClick(DialogPreference.java:264) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.preference.Preference.performClick(Preference.java:939) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.preference.PreferenceScreen.onItemClick(PreferenceScreen.java:202) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.widget.AdapterView.performItemClick(AdapterView.java:292) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.widget.AbsListView.performItemClick(AbsListView.java:1173) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2701) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.widget.AbsListView$1.run(AbsListView.java:3453) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.os.Handler.handleCallback(Handler.java:605) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.os.Handler.dispatchMessage(Handler.java:92) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.os.Looper.loop(Looper.java:137) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at android.app.ActivityThread.main(ActivityThread.java:4514) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at java.lang.reflect.Method.invokeNative(Native Method) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at java.lang.reflect.Method.invoke(Method.java:511) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557) 
02-28 13:37:15.768: E/AndroidRuntime(24732): at dalvik.system.NativeStart.main(Native Method)

來源

2013-02-28 Harry

我找不到channel_content_view.xml定義的任何列表視圖..這可能b以供空指針可能的原因。 – Rahil2952 2013-02-28 11:48:33

對不起，我看到了。我現在添加它 – Harry 2013-02-28 11:53:45

您的佈局沒有任何的ListView。

添加一個到你的LinearLayout中，給它一個ID，並用它來找到的ListView LV

來源

2013-02-28 11:48:28

哦，這使得sence，讓我試試 – Harry 2013-02-28 11:50:57

它會是ListView lv =（ListView）vw.findViewById（R.id.list）;如果我使用ID列表在LinearLayout中創建一個listview？ – Harry 2013-02-28 11:53:29

使用R.id.your_given_id，所以你確定你得到了正確的列表。在ListActivitys中，您可以使用Android.r ...一個，但是您仍然必須將其作爲Id提供給ListView。 – 2013-02-28 11:54:51

列表視圖的NullPointerException內onCreateDialogView

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