0
  1. Activity新しい を作成しThreadます。
  2. このメソッドは、入力ストリームを介しrun()てオブジェクト ( ) を取得します。vector
  3. 今度は、これの内容を呼び出さVectorれたに表示したいと思います。ListViewdirec
  4. それだけです...しかし、それは機能せず、Exception.

コード:

public class FileExplorerActivity extends Activity implements Runnable
{
    public static final String TAG="ricky";
    Vector<String> dirs = new Vector<String>();
    ListView direc;
    static ArrayAdapter<String> arrayAdapter;
    Handler handler;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fileexplorer);
        direc = (ListView) findViewById(R.id.directoriesss);
        handler = new Handler();
        Thread thread = new Thread(this);
        thread.start();
    }

    public FileExplorerActivity() 
    {

    }

    public void run()
    {
        Log.d(TAG, "FileExplorer: Thread started");
        try
        {
            Log.d(TAG, "FileExplorer: reading data");
            dirs = (Vector<String>) ConnectionThread.din.readObject();
            Log.d(TAG, "FileExplorer: read data");
            arrayAdapter = new ArrayAdapter<String>(this, 
                                     android.R.layout.activity_list_item,
                                     android.R.id.text2 , dirs);            
            Log.d(TAG, "FileExplorer: ArrayAdapter created");

            handler.post( new Runnable() {
                public void run()
                {
                    Log.d(TAG, "FileExplorer: In handler Thread");
                    direc.setAdapter(arrayAdapter);
                    Log.d(TAG, "FileExplorer: Updated UI");
                }
            });

            Log.d(TAG, "FileExplorer: Directory set");
        }catch (Exception e) {
            Log.d(TAG, "FileExplorerActivity: Exception:"+e.getMessage());
        }
    }
}

Logcat の説明は次のとおりです。

> 1. 05-24 20:14:46.601  7759  7834 D ricky   : FileExplorer: Thread started
> 2. 05-24 20:14:46.601  7759  7834 D ricky   : FileExplorer: reading data
> 3. 05-24 20:14:46.648  7759  7834 D ricky   : FileExplorer: read data
> 4. 05-24 20:14:46.648  7759  7834 D ricky   : FileExplorer: ArrayAdapter created
> 5. 05-24 20:14:46.648  7759  7834 D ricky   : FileExplorer: Directory set
> 6. 05-24 20:14:46.656  7759  7759 D ricky   : FileExplorer: In handler Thread
> 7. 05-24 20:14:46.656  7759  7759 D ricky   : FileExplorer: Updated UI
> 8. 05-24 20:14:46.664  7759  7759 D AndroidRuntime: Shutting down VM
> 9. 05-24 20:14:46.664  7759  7759 W dalvikvm: threadid=1: thread exiting with uncaught 10. exception (group=0x4001e560)
> 11. 05-24 20:14:46.687  7759  7759 E AndroidRuntime: FATAL EXCEPTION: main
> 12. 05-24 20:14:46.687  7759  7759 E AndroidRuntime: java.lang.NullPointerException
> 13. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:353)
> 14. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)
> 15. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.AbsListView.obtainView(AbsListView.java:1456)
> 16. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.ListView.measureHeightOfChildren(ListView.java :1291)
> 17. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.ListView.onMeasure(ListView.java:1202)
> 18. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.View.measure(View.java:8355)
> 19. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java :3279)
> 20. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017)
> 21. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.LinearLayout.measureHorizontal(LinearLayout.ja va:701)
> 22. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.LinearLayout.onMeasure(LinearLayout.java:311)
> 23. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.View.measure(View.java:8355)
> 24. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java :3279)
> 25. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
> 26. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.View.measure(View.java:8355)
> 27. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.LinearLayout.measureVertical(LinearLayout.java :531)
> 28. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
> 29. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.View.measure(View.java:8355)
> 30. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java :3279)
> 31. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
> 32. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.View.measure(View.java:8355)
> 33. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.ViewRoot.performTraversals(ViewRoot.java:882)
> 34. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.view.ViewRoot.handleMessage(ViewRoot.java:1917)
> 35. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.os.Handler.dispatchMessage(Handler.java:99)
> 36. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.os.Looper.loop(Looper.java:130)
> 37. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at android.app.ActivityThread.main(ActivityThread.java:3859)
> 38. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at java.lang.reflect.Method.invokeNative(Native Method)
> 39. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at java.lang.reflect.Method.invoke(Method.java:507)
> 40. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
> 41. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
> 42. 05-24 20:14:46.687  7759  7759 E AndroidRuntime:        at dalvik.system.NativeStart.main(Native Method)
4

2 に答える 2

1

NullPointerExceptionが発生する行に注意してください。

android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:353)


android.R.layout.activity_list_itemが含まれていないためandroid.R.id.text2です。

android.R.id.text1代わりにを使用するか、行レイアウトを に置き換えることができますsimple_list_item_2

そもそもこれらの状況を回避するために、独自の行レイアウトを作成することをお勧めします。

于 2012-05-24T15:29:49.693 に答える
0

これを動かして

arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.activity_list_item,
        android.R.id.text2 , dirs);

run() メソッド内で UI スレッドで実行されるようにします。UI スレッドの外部で ArrayAdapter を作成しないでください。

于 2012-05-24T15:34:41.873 に答える