我正在制作一个游戏,玩家可以在屏幕上拖放东西.我有一个私有方法,允许我为玩家可以移动的任何项目模拟拖放事件.对于拖动,我实际上离开视图他们触摸它的位置并创建一个新的ImageView,并从触摸的视图中将drawable设置为drawingCache,然后在他们的手指上围绕屏幕移动这个新创建的ImageView.当你松开手指(放下视图)时,我打电话myLayout.remove(movingImg);让它离开屏幕.我有一个问题,如果我开始一个模拟的拖动事件,然后手动拿起其他一个项目,我在myLayout.remove()调用上得到一个空指针,这里是来自日志的跟踪:
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): java.lang.NullPointerException
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2122)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.drawChild(ViewGroup.java:2506)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2123)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.drawChild(ViewGroup.java:2506)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2123)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.drawChild(ViewGroup.java:2506)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2123)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.drawChild(ViewGroup.java:2506)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2123)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.View.draw(View.java:9032)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.widget.FrameLayout.draw(FrameLayout.java:419)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1910)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewRoot.draw(ViewRoot.java:1608)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): at android.view.ViewRoot.performTraversals(ViewRoot.java:1329)
04-06 10:37:43.610: ERROR/AndroidRuntime(23203): …