我的应用程序的功能非常简单：
它在GridView上显示SD卡上所有图像的缩略图图像 以及这些缩略图一角的图标，以便用户可以触摸它以启动 拖动图像的阴影。
可以在已设置拖动侦听器的视图上删除此阴影。当那个 发生时，将使用图像文件路径Uri调用新的intent作为额外的 新意图。到目前为止，非常好。
当我开始在没有任何视图的视图上删除阴影时会发生问题 拖动监听器，最终冻结屏幕并使移动设备崩溃！
我进入堆栈跟踪的所有内容是：
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（我执行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);
}
}
}
关于这里发生了什么的任何想法/线索？我真的很感激这一点。
提前致谢。
答案 0 :(得分：1)
如果你的'onDrag（View v，DragEvent事件）'方法中有switch case语句，那么你应该在那里添加'DragEvent.ACTION_DRAG_LOCATION'。在那里，您可以定义，如果您的图标/图像放置在非拖动字段上会发生什么。
以下是一个例子：
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;
}
}
}
答案 1 :(得分：1)
我遇到了类似的问题，因为我不希望布局接受放置操作。
通过setOnDragListener将拖动侦听器附加到视图。
view.setOnDragListener（new MyDragListener（））;
检查onDrag事件中的目标视图是否为您所需的视图。如果条件为假，请将所需的代码放在那里。
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
}