Android 多点触控错误处理（java.lang.IllegalArgumentException: pointerIndex out of range）
最近做View的多点触控时，每次第一次触控事件完美运行，第二次就直接崩了，错误信息如下：
01-03 00:05:44.220 4377-4410/system_process E/AndroidRuntime: *** FATAL EXCEPTION IN SYSTEM PROCESS: android.ui
java.lang.IllegalArgumentException: pointerIndex out of range
at android.view.MotionEvent.nativeGetAxisValue(Native Method)
at android.view.MotionEvent.getX(MotionEvent.java:2072)
at com.android.server.policy.EnableAccessibilityController.onTouchEvent(EnableAccessibilityController.java:193)
at com.android.server.policy.GlobalActions.onTouch(GlobalActions.java:1077)
at android.view.View.dispatchTouchEvent(View.java:9404)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2660)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2304)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2666)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
at com.android.internal.policy.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2447)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1766)
at android.app.Dialog.dispatchTouchEvent(Dialog.java:797)
at com.android.internal.policy.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2408)
at android.view.View.dispatchPointerEvent(View.java:9646)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4738)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4596)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4101)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4154)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4120)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4266)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4128)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4323)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4101)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4154)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4120)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4128)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4101)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6555)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6529)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6472)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6727)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:176)
at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:6686)
at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:6753)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:894)
at android.view.Choreographer.doCallbacks(Choreographer.java:696)
at android.view.Choreographer.doFrame(Choreographer.java:625)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:880)
at android.os.Handler.handleCallback(Handler.java:815)
at android.os.Handler.dispatchMessage(Handler.java:104)
at android.os.Looper
解决方案：
这个bug是Android系统原因 所以第一种方式是：
修改frameworks\base\core\jni\android_view_MotionEvent.cpp的android_view_MotionEvent_nativeGetAxisValue方法
注释掉
[java]
if (!validatePointerIndex(env, pointerIndex, pointerCount)) {return 0;｝
改完后需重新编译整个系统，然后替换lib库，重新编译整个系统，这个方法就比较麻烦了
第二种方法是：捕获IllegalArgumentException（非法参数异常）异常 即如
[java]
private float spacing(MotionEvent event) {
try {
x = event.getX(0) - event.getX(1);
y = event.getY(0) - event.getY(1);
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
第二种方法简单有效。
