我通過setVisibility(View.INVISIBLE)
隱藏視圖。後來,當我試圖表明的觀點再次在不同的方法,通過setVisibility(View.VISIBLE)
我得到下面的異常Android - setVisibility結果java.util.ConcurrentModificationException
03-28 01:32:05.450: E/AndroidRuntime(20895): FATAL EXCEPTION: main
03-28 01:32:05.450: E/AndroidRuntime(20895): java.util.ConcurrentModificationException
03-28 01:32:05.450: E/AndroidRuntime(20895): at java.util.HashMap$HashIterator.nextEntry(HashMap.java:796)
03-28 01:32:05.450: E/AndroidRuntime(20895): at java.util.HashMap$KeyIterator.next(HashMap.java:823)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:946)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:948)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:948)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:948)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:948)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:948)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.view.ViewRoot.handleDragEvent(ViewRoot.java:3027)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.view.ViewRoot.handleMessage(ViewRoot.java:2185)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.os.Handler.dispatchMessage(Handler.java:99)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.os.Looper.loop(Looper.java:132)
03-28 01:32:05.450: E/AndroidRuntime(20895): at android.app.ActivityThread.main(ActivityThread.java:4028)
03-28 01:32:05.450: E/AndroidRuntime(20895): at java.lang.reflect.Method.invokeNative(Native Method)
03-28 01:32:05.450: E/AndroidRuntime(20895): at java.lang.reflect.Method.invoke(Method.java:491)
03-28 01:32:05.450: E/AndroidRuntime(20895): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:844)
03-28 01:32:05.450: E/AndroidRuntime(20895): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
03-28 01:32:05.450: E/AndroidRuntime(20895): at dalvik.system.NativeStart.main(Native Method)
當我註釋掉改變能見度回到可見行了,我不明白的例外。
我首先想到的是,其他代碼會通過hashmap迭代引發異常,但是,在迭代我使用的hashmaps時,我沒有做任何修改,我也沒有多線程,這似乎是這種例外的最常見原因。當我不改變能見度時,我也不例外。
編輯:
自定義片段中發生異常。下面是迭代散列圖(mWidgetConfig
)的代碼,其中包含有關我嘗試還原的自定義窗口小部件配置的信息。散列映射是片段中的公共變量。
在由所述片段創建的OnDragListener
,我按一定的拖動操作更新的散列映射,如下:
// Update the widget configuration of the fragment that created this listener
mFragment.mWidgetConfig.put(startCircleTag, "0");
我還遍歷散列映射,以檢查特定的條件,但我不在迭代過程中做任何修改:
Iterator<String> keySetItr = mFragment.mWidgetConfig.keySet().iterator();
while(keySetItr.hasNext()) {
String tag = keySetItr.next();
if(mFragment.mWidgetConfig.get(tag).equals((String) destSocket.getTag())) {
// do something, though no modification of the hashmap
break;
}
}
另外,我在片段本身做了一次迭代,同時嘗試恢復窗口小部件的配置。下面是我用根據HashMap來配置插件的代碼:
public void configureWidgets() {
resetWidgets();
Iterator<String> keySetItr = mWidgetConfig.keySet().iterator();
while(keySetItr.hasNext()) {
String tag = keySetItr.next();
Integer value = Integer.parseInt(mWidgetConfig.get(tag));
ImageView destSocket = null;
switch(value) {
case 0:
// The circle will not be connected to any socket
continue;
case 1:
destSocket = mSocket1;
break;
case 2:
destSocket = mSocket2;
break;
case 3:
destSocket = mSocket3;
break;
}
ImageView startCircle = (ImageView) mLayout.findViewWithTag(tag);
ImageView startPlug = (ImageView) mLayout.findViewWithTag(tag + "_plug");
// Replace the drawable of destSocket
destSocket.setBackgroundDrawable(getActivity().getResources().getDrawable(R.drawable.socket_plugged));
// Hide plug view
startPlug.setVisibility(View.INVISIBLE);
// Draw a line between the start circle view and the destination socket view
mConnectionLinesView.addLine(startCircle, destSocket);
}
}
public void resetWidgets() {
// Remove all lines
mConnectionLinesView.removeLines();
// Show all eventually previously hidden plugs
//mPlug1.setVisibility(View.VISIBLE);
//mPlug2.setVisibility(View.VISIBLE);
//mPlug3.setVisibility(View.VISIBLE);
// Set to backround drawable of the socket to the initial one
mSocket1.setBackgroundDrawable(getActivity().getResources().getDrawable(R.drawable.socket).mutate());
mSocket2.setBackgroundDrawable(getActivity().getResources().getDrawable(R.drawable.socket).mutate());
mSocket3.setBackgroundDrawable(getActivity().getResources().getDrawable(R.drawable.socket).mutate());
}
只要是上面設置在代碼中使用的「插頭」的知名度線,我得到的異常。
SOLUTION
究其原因,除了得到拋出的是我叫的OnDragListener
的DragEvent.ACTION_DRAG_ENDED
case語句的配置方法。當我將相同的代碼放入DragEvent.ACTION_DROP
case語句時,該異常不會被拋出。不知道爲什麼。感謝您的幫助球員
發佈迭代hashmap的代碼...並創建這個異常 – 2012-03-28 10:29:51
,那麼當我更改可見性時,怎麼纔會拋出異常呢? – Schnodahipfe 2012-03-28 14:51:35
正在刪除或添加'while(iterator.hasNext())' – 2012-03-28 14:55:04