Android的阻力和ICS中的图片崩溃（4.0.3）

Question

我的应用程序做什么是很简单：

它显示上一个GridView 的SD卡和角落的图标所有图像的缩略图这些缩略图让用户可以触摸它来启动 拖动图像的阴影。

该阴影可以放在已经设置了拖动监听器的视图上。当 发生时，新的意图将被调用，图像文件路径Uri将作为 新意图的额外内容。到现在为止还挺好。

问题发生在我开始在没有任何 拖动监听器的视图上放下阴影时，最终会冻结屏幕并使移动设备崩溃！

所有我在堆栈跟踪得到的是这样的：

03-29 14:24:14.803: I/ViewRootImpl(2496): Reporting drop result: false 
03-29 14:24:14.803: W/WindowManager(274): Drag is in progress but there is no drag window handle. 
03-29 14:24:15.062: I/ViewRootImpl(2496): Reporting drop result: false 
03-29 14:24:15.062: W/WindowManager(274): Drag is in progress but there is no drag window handle. 
03-29 14:24:15.294: I/ViewRootImpl(2496): Reporting drop result: false 
03-29 14:25:06.972: I/Process(274): Sending signal. PID: 274 SIG: 3 
03-29 14:25:06.972: I/dalvikvm(274): threadid=3: reacting to signal 3 
03-29 14:25:07.092: I/dalvikvm(274): Wrote stack traces to '/data/anr/traces.txt' 
03-29 14:25:10.012: W/ActivityManager(274): Timeout of broadcast BroadcastRecord{2c09ce28 android.intent.action.TIME_TICK} - receiver=android.app.LoadedApk$ReceiverDispatcher$InnerReceiver@2bf0c4e8, started 10009ms ago 
03-29 14:25:10.012: W/ActivityManager(274): Receiver during timeout: BroadcastFilter{2bf0cd08 ReceiverList{2bf0c660 274 system/1000 local:2bf0c4e8}} 
03-29 14:25:20.022: W/ActivityManager(274): Timeout of broadcast BroadcastRecord{2c09ce28 android.intent.action.TIME_TICK} - receiver=android.app.LoadedApk$ReceiverDispatcher$InnerReceiver@2bef04e8, started 10008ms ago 
03-29 14:25:20.022: W/ActivityManager(274): Receiver during timeout: BroadcastFilter{2bef0760 ReceiverList{2bef06e8 274 system/1000 local:2bef04e8}} 
03-29 14:25:37.092: W/Watchdog(274): WATCHDOG PROBLEM IN SYSTEM SERVER: com.android.server.wm.WindowManagerService 
03-29 14:25:37.102: I/Process(274): Sending signal. PID: 274 SIG: 3 
03-29 14:25:37.102: I/dalvikvm(274): threadid=3: reacting to signal 3 
03-29 14:25:37.182: I/dalvikvm(274): Wrote stack traces to '/data/anr/traces.txt' 
03-29 14:25:37.192: I/Process(274): Sending signal. PID: 475 SIG: 3 
03-29 14:25:37.192: I/dalvikvm(475): threadid=3: reacting to signal 3 
03-29 14:25:37.202: I/dalvikvm(475): Wrote stack traces to '/data/anr/traces.txt' 
03-29 14:25:39.204: I/Watchdog_N(274): dumpKernelStacks 
03-29 14:25:39.492: I/CrashMonitor(1186): CrashMonitorService: invokeService: android.intent.action.DROPBOX_ENTRY_ADDED 
03-29 14:25:39.492: W/Watchdog(274): *** WATCHDOG KILLING THE SYSTEM: com.android.server.wm.WindowManagerService 

我的适配器类（其中i执行view.startDrag（）方法）：

public class ImageCursorAdapter extends CursorAdapter { 

    private LayoutInflater mInflater; 
    private final static int mImageColumnID = 0; 
    private Options mOptions = new Options();; 
    private Cursor mCursor; 

    public ImageCursorAdapter(Context context, Cursor c) { 
     super(context, c); 

     mInflater = LayoutInflater.from(context); 
     mOptions.inSampleSize = 4; 
    } 

    @Override 
    public void bindView(View view, Context context, Cursor cursor) { 
     mCursor = cursor; 
     ViewHolder holder = (ViewHolder) view.getTag(); 
     ImageThumbnailLoader imageLoader = new ImageThumbnailLoader(
      holder.thumbImg, cursor.getLong(mImageColumnID), 
      context.getContentResolver(), false); 
     imageLoader.execute(); 
//  holder.thumbImg.setImageBitmap(MediaStore.Images.Thumbnails.getThumbnail(
//     context.getContentResolver(), cursor.getLong(mColumnID), 
//     MediaStore.Images.Thumbnails.MICRO_KIND, mOptions)); 
     holder.dragImg.setTag(holder.thumbImg); 
     holder.dragImg.setId(cursor.getPosition()); 
     holder.dragImg.setOnTouchListener(new OnTouchListener() { 

      @Override 
      public boolean onTouch(View v, MotionEvent event) { 
       int action = event.getAction(); 
       if (action == MotionEvent.ACTION_DOWN) { 
        mCursor.moveToPosition(v.getId()); 
        int dataColumn = mCursor.getColumnIndex(MediaStore.Images.Media.DATA); 
        ClipData dragData = ClipData.newPlainText("filename", 
         mCursor.getString(dataColumn)); 
        DragShadowBuilder shadow = new DragShadowBuilder((View) v.getTag()); 
        return v.startDrag(dragData, shadow, null, 0); 
       } 
       return false; 
      } 
     }); 
     Log.i("Prototype", "bindView : " + cursor.getPosition()); 
    } 

    @Override 
    public View newView(Context context, Cursor cursor, ViewGroup parent) { 
     Log.i("Prototype", "newView : " + cursor.getPosition()); 
     View view = mInflater.inflate(R.layout.grid_item, null); 
     ViewHolder holder = new ViewHolder(view); 
     view.setTag(holder); 
     return view; 
    } 


    private static class ViewHolder { 
     ImageView thumbImg, dragImg; 

     ViewHolder(View base) { 
      thumbImg = (ImageView) base.findViewById(R.id.thumbImage); 
      dragImg = (ImageView) base.findViewById(R.id.dragImage); 
     } 
    } 

} 

任何想法/上what`线索在这里呢？我真的很感激这一点。

在此先感谢。

Answer 1

如果在'onDrag（View v，DragEvent event）'方法中有switch case语句，那么您应该在那里添加'DragEvent.ACTION_DRAG_LOCATION'的情况。在那里你可以定义，如果你的图标/图像放置在非拖动字段上会发生什么。

下面是一个例子：

public class MyDragListener implements OnDragListener { 

    @Override 
    public boolean onDrag(View v, DragEvent event) { 
    int action = event.getAction(); 
    switch (action) { 
    case DragEvent.ACTION_DRAG_STARTED: 
     break; 
    case DragEvent.ACTION_DRAG_ENTERED: 
     break; 
    case DragEvent.ACTION_DRAG_EXITED: 
     break; 
    case DragEvent.ACTION_DROP: 
     View view = (View) event.getLocalState(); 
     ViewGroup owner = (ViewGroup) view.getParent(); 
     owner.removeView(view); 
     RelativeLayout container = (RelativeLayout) v; 
     container.addView(view); 
     view.setVisibility(View.VISIBLE); 
     break; 
    case DragEvent.ACTION_DRAG_ENDED: 
        break; 
    case DragEvent.ACTION_DRAG_LOCATION: 
     view.setVisibility(View.VISIBLE); 
     break; 
    } 
    } 

} 

Answer 2

我遇到在一个类似的问题，我不想布局接受拖放操作。

通过setOnDragListener将一个拖拽监听器附加到您的视图。

view.setOnDragListener（new MyDragListener（））;

检查onDrag事件中的目标视图是否为您需要的视图。如果条件不成立，请将您想要的代码放在那里。

class MyDragListener implements OnDragListener { 

@Override 
public boolean onDrag(View v, DragEvent event) { 

    switch (event.getAction()) { 
    case case DragEvent.ACTION_DROP: 
     //check whether it has not been dropped onto your view 
      if(v!=view) 
       //your code here 
}