java - 关于Android的Instrumentation和TouchEvent

Question

instrumentation.sendPointerSync(MotionEvent.obtain(SystemClock.uptimeMillis(),SystemClock.uptimeMillis(), MotionEvent.ACTION_DOWN, dx, dy, 0));
instrumentation.sendPointerSync(MotionEvent.obtain(SystemClock.uptimeMillis(),SystemClock.uptimeMillis(), MotionEvent.ACTION_MOVE, mx, my, 0));
instrumentation.sendPointerSync(MotionEvent.obtain(SystemClock.uptimeMillis(),
SystemClock.uptimeMillis(), MotionEvent.ACTION_UP, upx, upy, 0));

用Instrumentation模拟手指的滑动 但是我给view添加了一个TouchListener收到的Action却只有一个MotionEvent.CANCEL这是什么情况