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我有得到我的方法创建的HashMap
ConcurrentModificationException的与ViewTreeObserver onPreDrawLstener
final HashMap<Long, Rect> listViewItemBounds = new HashMap<Long, Rect>();
,节省的可见视图所有的界限在ListView
for (int i = 0; i < getChildCount(); ++i) {
View child = getChildAt(i);
if(child != null){
int position = firstVisiblePosition+i;
long itemID = adapter.getItemId(position);
Rect startRect = new Rect(child.getLeft(), child.getTop(), child.getRight(),child.getBottom());
listViewItemBounds.put(itemID, startRect);
listViewItemDrawables.put(itemID, getBitmapDrawableFromView(child));
}
}
然后我在ListView控件启动OnPreDrawListener
final ViewTreeObserver observer = getViewTreeObserver();
observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
public boolean onPreDraw() {
.
.
.
}
)};
and in the通过他onPreDrawListener我环路HashMap来获取已保存的视图边界
for (Long itemId: listViewItemBounds.keySet()) { //points here
.
.
.
istViewItemBounds.remove(itemId);
}
当我改变/更新,其中这一切都被一次onPreDraw
称为当前通过HashMap的循环,而它正在更新适配器问题就来了再次由于适配器的变化。
那么我该如何防止这里的并发,所以我没有得到ConcurrentModificationException
?
堆栈跟踪:
08-31 19:09:41.398 29127-29127/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:792)
at java.util.HashMap$KeyIterator.next(HashMap.java:819)
at com.tyczj.myapp.views.HeaderGridView$3.onPreDraw(HeaderGridView.java:511)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:680)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1842)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
at android.view.Choreographer.doCallbacks(Choreographer.java:562)
at android.view.Choreographer.doFrame(Choreographer.java:532)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
编辑:
Iterator<Long> it = listViewItemBounds.keySet().iterator();
while(it.hasNext()){
long itemId = it.next(); //error
}
你是对的,我没有。 Mea culpa没有看到remove()调用。 – 2014-09-01 00:04:59
不用担心。我第一次尝试回答这个问题并不完全清楚 - 我试图在移动设备上输入代码,但获得的成功有限。 – 2014-09-01 00:12:27
ok看到我的编辑,我改变了使用'Iterator',但现在我得到'it.next()'的错误,我错过了什么? – tyczj 2014-09-01 00:15:22