在我的多点触摸程序中,我遇到了一个运行时错误,其中指针在屏幕上滑动的多点触逻辑(MotionEvent.ACTION_MOVE)仅由初始指针输入。这意味着我的switch语句中的ACTION_MOVE的代码只能通过第一根手指触摸屏幕访问,也就是指针索引=0。以下是我的代码的相关部分:
public boolean onTouchEvent(MotionEvent event) {
// get pointer index from the event object
int pointerIndex = event.getActionIndex();
// get pointer ID
int pointerId = event.getPointerId(pointerIndex);
// get masked (not specific to a pointer) action
int maskedAction = event.getActionMasked();
switch (maskedAction) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_DOWN: {
// We have a new pointer. Lets add it to the list of pointers
PointF f = new PointF();
f.x = event.getX(pointerIndex);
f.y = event.getY(pointerIndex);
mActivePointers.put(pointerId, f);
Log.d("Multitouch", "x coord = " + Float.toString(f.x));
Log.d("Multitouch", "y coord = " + Float.toString(f.y));
break;
}
case MotionEvent.ACTION_MOVE: { // a pointer was moved
Log.e("Multitouch", "Pointer"+ Integer.toString(pointerId) +" is moving");
for (int size = event.getPointerCount(), i = 0; i < size; i++) {
PointF f = mActivePointers.get(event.getPointerId(i));
if (f != null) {
f.x = event.getX(i);
f.y = event.getY(i);
}
}
break;
}
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL: {
mActivePointers.remove(pointerId);
break;
}
}
invalidate();
return true;
}
不用说,我希望Action_Move中的代码由任何指针触发,而不仅仅是初始指针。是什么防止索引零以外的指针触发移动事件?
