为什么MotionEvent模拟不工作？ [英] Why doesn't this MotionEvent simulation work?

问题描述

我可以（以编程方式）输入文本选择模式，视图左上角的CursorControllers（AKA手柄）可视地指示。

如果我手动拖动右侧的CursorController，然后再次点击它（在模拟器中），它按预期（完美）工作，显示一条简短的消息：文本复制到剪贴板。

但是当我尝试以编程方式拖动正确的CursorController，没有任何反应。

我尝试这样做的方法是模拟MotionEvent。在视图中，我打电话给：

  event = MotionEvent.obtain（downTime，eventTime，MotionEvent.ACTION_DOWN，x，y，0 ）; 
 MainActivity.onTouch（this，event）; 
  

在MainActivity我当然实现OnTouchListener：

$ {code> @Override
public boolean onTouch（View v，MotionEvent event）{//调用BEFORE按钮的onTouchEvent（）
Log.v（MainActivity :: onTouch （），describeEvent（v，event））;
switch（event.getAction（））{
case MotionEvent.ACTION_DOWN：
case MotionEvent.ACTION_UP：
if（！v.hasFocus（））{
v .requestFocus（）;
}
break;
}
返回false;
}

如果我理解正确，只需从onTouch返回false， Android不断寻找另一个UI对象来使用MotionEvent对象，最终达到我的观点。

为什么不会发生？

我必须遗漏一些非常基本的东西...

解决方案

解决方案，我只能得出结论，为安全起见，我一直在努力完成的事情在Android上是不可能的。以下链接可以找到解释：如何通过系统发送合成的MotionEvent？

In one of the views in an exercise app, am trying to perform text selection programmatically.

I am able to (programmatically) enter "text selection mode", which is visually indicated by CursorControllers (AKA handles) on the top-left corner of the view.

If I manually drag the right CursorController, then click it again (in the emulator), it works as expected (perfectly), showing a brief message: "Text copied to clipboard".

But when I try to programmatically drag that right CursorController, nothing happens.

The way I try to do this is by simulating a MotionEvent. In the view, I call:

  event = MotionEvent.obtain(downTime, eventTime, MotionEvent.ACTION_DOWN, x, y, 0);
  MainActivity.onTouch(this, event);

In the MainActivity I of course implement OnTouchListener:

@Override
public boolean onTouch(View v, MotionEvent event) { // called BEFORE button's onTouchEvent()
    Log.v("MainActivity::onTouch()", describeEvent(v, event));
    switch (event.getAction()) { 
        case MotionEvent.ACTION_DOWN: 
        case MotionEvent.ACTION_UP: 
            if (!v.hasFocus()) { 
                v.requestFocus(); 
             } 
             break; 
    } 
    return false; 
}

If I understand correctly, by mere returning 'false' from onTouch, Android keeps looking for another UI object to consume the MotionEvent object, eventually reaching my view.

Why doesn't this happen?

I must be missing something very fundamental...

解决方案

For lack of a working solution, I can only conclude that what I have been trying to accomplish isn't possible on the Android, for reasons of security. An explanation can be found in the following link: How to send synthesized MotionEvent through the system?

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