android：光標適配器空指針

我在我的一個應用程序中有以下代碼。我得到一個運行時錯誤在這個android：光標適配器空指針

public class MainActivity extends Activity { 
    private SQLiteAdapter mySQLiteAdapter; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     // TODO Auto-generated method stub 
     super.onCreate(savedInstanceState); 
     ListView listContent = (ListView) findViewById(R.id.listView1); 
     mySQLiteAdapter = new SQLiteAdapter(this); 
     mySQLiteAdapter.openToRead(); 
     Cursor cursor = mySQLiteAdapter.queueAll(); 
     startManagingCursor(cursor); 
     String[] from = new String[] { SQLiteAdapter.KEY_CONTENT }; 
     int[] to = new int[] { R.id.textView1, R.id.textView2 }; 
     SimpleCursorAdapter cursorAdapter = new SimpleCursorAdapter(this, 
       R.layout.row, cursor, from, to); 
     listContent.setAdapter(cursorAdapter); 
     mySQLiteAdapter.close(); 
    } 
}

錯誤如下：

06-08 00:04:17.133: E/AndroidRuntime(7072): FATAL EXCEPTION: main 
06-08 00:04:17.133: E/AndroidRuntime(7072): java.lang.RuntimeException: Unable to start activity ComponentInfo{bl.ock/bl.ock.MainActivity}: java.lang.NullPointerException 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1768) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1784) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.app.ActivityThread.access$1500(ActivityThread.java:123) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.os.Handler.dispatchMessage(Handler.java:99) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.os.Looper.loop(Looper.java:130) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.app.ActivityThread.main(ActivityThread.java:3835) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at java.lang.reflect.Method.invokeNative(Native Method) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at java.lang.reflect.Method.invoke(Method.java:507) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at dalvik.system.NativeStart.main(Native Method) 
06-08 00:04:17.133: E/AndroidRuntime(7072): Caused by: java.lang.NullPointerException 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at bl.ock.MainActivity.onCreate(MainActivity.java:28) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1722) 
06-08 00:04:17.133: E/AndroidRuntime(7072):  ... 11 more

請幫我解決這個問題。謝謝你。獲得使用findViewById列表之前

來源

2012-06-07 Vishnu Mohan G

護理指向我們**線28 **？ –

line 28：listContent.setAdapter（cursorAdapter）; –

可能重複[什麼是空指針異常，以及如何解決它？]（http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do -i-fix-it） –

setContetView(<your_layout_id>) in missing in onCreate()（）函數

super.onCreate(savedInstanceState); 
    setContetView(<your_layout_id>);<------------------ 
    ListView listContent = (ListView) findViewById(R.id.listView1);

來源

2012-06-07 18:41:49

哈哈，那是一個愚蠢的錯誤。感謝您指出：D –

android：光標適配器空指針

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