dispatchKeyEvent（）调用两次 [英] dispatchKeyEvent() invoking twice

问题描述

我调试下面的代码片断和谙 dispatchKeyEvent（）被调用两次方法。请建议的解决方案

  @覆盖
公共布尔dispatchKeyEvent（KeyEvent的事件）{
如果（event.getKey code（）== KeyEvent.KEY code_DPAD_CENTER）
    {
        如果（cDetail.getVisibility（）== View.VISIBLE）
        {            cDetail.setVisibility（View.INVISIBLE）;
            cList.setVisibility（View.INVISIBLE）;
        }        其他
        {            cDetail.setVisibility（View.VISIBLE）;
            cList.setVisibility（View.VISIBLE）;        }
    }    返回super.dispatchKeyEvent（事件）;
}
 

解决方案

dispatchKeyEvent火两次：第一次键不放，并为关键了第二次，所以你必须进行过滤：

 如果（event.getAction（）！= KeyEvent.ACTION_DOWN）
                返回true;            开关（键code）{
            案例KeyEvent.KEY code_1：
                MakeToast（1）;
                打破;
            案例KeyEvent.KEY code_2：
                MakeToast（2）;
                打破;
            案例KeyEvent.KEY code_3：
                MakeToast（3）;
                打破;            }
 

I debugged the following snippet and come to know the method dispatchKeyEvent() is invoked twice. please suggest the solution

    @Override
public boolean dispatchKeyEvent(KeyEvent event) {
if(event.getKeyCode()== KeyEvent.KEYCODE_DPAD_CENTER)
    {
        if(cDetail.getVisibility()==View.VISIBLE  )
        {

            cDetail.setVisibility(View.INVISIBLE);
            cList.setVisibility(View.INVISIBLE);
        }

        else
        {

            cDetail.setVisibility(View.VISIBLE);
            cList.setVisibility(View.VISIBLE);

        }   


    }

    return super.dispatchKeyEvent(event);
}

解决方案

dispatchKeyEvent fire twice: the first time for key down, and the second time for key up, so you have to filter:

 if (event.getAction()!=KeyEvent.ACTION_DOWN)
                return true;

            switch (keyCode) {
            case KeyEvent.KEYCODE_1 : 
                MakeToast(1);
                break;
            case KeyEvent.KEYCODE_2 : 
                MakeToast(2);
                break;
            case KeyEvent.KEYCODE_3 : 
                MakeToast(3);
                break;

            }

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