android – Drag’n’Drop ConcurentModificationException

概述OnDragListener： @Overridepublic boolean onDrag(View v, DragEvent event) { switch (event.getAction()) { case DragEvent.ACTION_DRAG_ENTERED: switch (v.getId()) { OnDragListener：

@OverrIDepublic boolean onDrag(VIEw v,DragEvent event) {    switch (event.getAction()) {        case DragEvent.ACTION_DRAG_ENTERED:            switch (v.getID()) {                case R.ID.delete_zone: {                    addToShowCaseZone.setimageDrawable(getResources().getDrawable(R.drawable.showcase_2));                    inAddToShowcasesZone = true;                    break;                }                case MagazineGrIDAdapter.ID: {                    enteredVIEw = v;                    break;                }            }            return false;        case DragEvent.ACTION_DRAG_EXITED: {            switch (v.getID()) {                case R.ID.delete_zone: {                    addToShowCaseZone.setimageDrawable(getResources().getDrawable(R.drawable.showcase_1));                    inAddToShowcasesZone = false;                    break;                }                case MagazineGrIDAdapter.ID: {                    enteredVIEw = null;                    break;                }            }            return true;        }        case DragEvent.ACTION_DRAG_STARTED:            return true;        case DragEvent.ACTION_DRAG_LOCATION:            return false;        case DragEvent.ACTION_DROP: {            if (inAddToShowcasesZone) {                final int position = grIDVIEw.getpositionForVIEw(dragVIEw);                Magazine magazine = magazineAdapter.getItem(position);                try {                    new Magazine(magazine.getUrl().toString(),magazine.getimage(),magazine.getBackgroundNum(),magazine.getname());                } catch (MalformedURLException e) {                    e.printstacktrace();                }                addToShowCaseZone.setimageDrawable(getResources().getDrawable(R.drawable.showcase_1));                inAddToShowcasesZone = false;                magazineAdapter.deleteFromList(position);                return false;            } else if(enteredVIEw != null && !enteredVIEw.equals(dragVIEw)){                ResourcesForNativeMagazines.swAPItems(grIDVIEw.getpositionForVIEw(dragVIEw),grIDVIEw.getpositionForVIEw(enteredVIEw),tabNumber - 1);                magazineAdapter.refreshValues(ResourcesForNativeMagazines.getMagazines(tabNumber - 1));                enteredVIEw = null;                return false;            }            dragVIEw.setVisibility(VISIBLE);            return false;        }        default:            dragVIEw.setVisibility(VISIBLE);            return true;    }}

适配器部件：

public voID refreshValues(List<Magazine> magazines){    this.magazines = new ArrayList<>(magazines);    notifyDataSetChanged();}public voID deleteFromList(int position){    magazines.remove(position);    notifyDataSetChanged();}

有时这个代码在我删除项目时调用方法refreshValuews和deleteFromList中的错误,这是它的堆栈跟踪：

java.util.ConcurrentModificationException        at java.util.HashMap$HashIterator.nextEntry(HashMap.java:806)        at java.util.HashMap$KeyIterator.next(HashMap.java:833)        at androID.vIEw.VIEwGroup.dispatchDragEvent(VIEwGroup.java:1172)        at androID.vIEw.VIEwGroup.dispatchDragEvent(VIEwGroup.java:1174)        at androID.vIEw.VIEwGroup.dispatchDragEvent(VIEwGroup.java:1174)        at androID.vIEw.VIEwGroup.dispatchDragEvent(VIEwGroup.java:1174)        at androID.vIEw.VIEwGroup.dispatchDragEvent(VIEwGroup.java:1174)        at androID.vIEw.VIEwGroup.dispatchDragEvent(VIEwGroup.java:1174)        at androID.vIEw.VIEwGroup.dispatchDragEvent(VIEwGroup.java:1174)        at androID.vIEw.VIEwRootImpl.handleDragEvent(VIEwRootImpl.java:4911)        at androID.vIEw.VIEwRootImpl.access0(VIEwRootImpl.java:94)        at androID.vIEw.VIEwRootImpl$VIEwRootHandler.handleMessage(VIEwRootImpl.java:3188)        at androID.os.Handler.dispatchMessage(Handler.java:99)        at androID.os.Looper.loop(Looper.java:137)        at androID.app.ActivityThread.main(ActivityThread.java:5103)        at java.lang.reflect.Method.invokeNative(Native Method)        at java.lang.reflect.Method.invoke(Method.java:525)        at com.androID.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)        at com.androID.internal.os.ZygoteInit.main(ZygoteInit.java:553)        at dalvik.system.NativeStart.main(Native Method)

我应该怎么解决？有没有其他方法可以通过拖放来修改grIDVIEw中的项目？

解决方法 我找到了一个解决方案,不要引起你应该做的下一个例外：

public boolean onDrag(VIEw v,DragEvent event) {    switch (event.getAction()) {        case DragEvent.ACTION_DRAG_ENDED:{            v.post(new Runnable{                public voID run() {                    //SomeCode;                }            });        break;        }      }}

总结

以上是内存溢出为你收集整理的android – Drag’n’Drop ConcurentModificationException全部内容，希望文章能够帮你解决android – Drag’n’Drop ConcurentModificationException所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。