Android按键处理

在activity中重写了dispatchKeyEvent事件，不论最后返回TRUE还是FALSE都不会执行onKeyDown事件了么？

找到的一些资料却不是这样解释的：
当键盘按下时
首先触发dispatchKeyEvent
然后触发onUserInteraction
再次onKeyDown
如果按下紧接着松开，则是俩步
紧跟着触发dispatchKeyEvent
然后触发onUserInteraction

再次onKeyUp

dispatchKeyEvent是做按键处理和分发的工作，如果你想要onKeyDown还可以接收到应该这样实现
public boolean dispatchKeyEvent(KeyEvent event){
return super.dispatchKeyEvent(event);
}

代码测试如下：

在dispatchKeyEvent(KeyEvent event)中按键的按下抬起都会进行操作，在处理完一个按键操作时无论return true 还是 false ，onKeyDown(int keyCode, KeyEvent event)和onKeyUp(int keyCode, KeyEvent event)都不会再进行按键处理：

第1种情况及log信息：

public void DEBUG(String str) {
        Log.d(TAG, str);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        DEBUG(" onKeyDown " + keyCode );
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public boolean onKeyLongPress(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        DEBUG("  onKeyLongPress " + keyCode );
        return super.onKeyLongPress(keyCode, event);
    }
    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        // TODO Auto-generated method stub
        DEBUG("  dispatchKeyEvent 1 key = " + event.getKeyCode() + " event =  " + event.getAction());
        if(event.getAction()==KeyEvent.ACTION_DOWN){
            DEBUG("  dispatchKeyEvent 2 ACTION_DOWN" + event.getKeyCode() );
            return super.dispatchKeyEvent(event);
        }
        if(event.getAction()==KeyEvent.ACTION_UP){
            DEBUG("  dispatchKeyEvent 3 ACTION_UP" + event.getKeyCode() );
            return super.dispatchKeyEvent(event);
        }
        return super.dispatchKeyEvent(event);
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        DEBUG(" onKeyUp " +  keyCode);
        return super.onKeyUp(keyCode, event);
    }

log信息：

D/ testMainActivity (  853):   dispatchKeyEvent 1 key = 23 event =  0
D/ testMainActivity (  853):   dispatchKeyEvent 2 ACTION_DOWN23
D/ testMainActivity (  853):  onKeyDown 23
D/ testMainActivity (  853):   dispatchKeyEvent 1 key = 23 event =  1
D/ testMainActivity (  853):   dispatchKeyEvent 3 ACTION_UP23
D/ testMainActivity (  853):  onKeyUp 23

第2种情况及log信息：

<pre name="code" class="java"><pre name="code" class="java"><pre name="code" class="java">public void DEBUG(String str) {
        Log.d(TAG, str);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        DEBUG(" onKeyDown " + keyCode );
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public boolean onKeyLongPress(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        DEBUG("  onKeyLongPress " + keyCode );
        return super.onKeyLongPress(keyCode, event);
    }
    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        // TODO Auto-generated method stub
        DEBUG("  dispatchKeyEvent 1 key = " + event.getKeyCode() + " event =  " + event.getAction());
        if(event.getAction()==KeyEvent.ACTION_DOWN){
            DEBUG("  dispatchKeyEvent 2 ACTION_DOWN" + event.getKeyCode() );
            return true;
        }
        if(event.getAction()==KeyEvent.ACTION_UP){
            DEBUG("  dispatchKeyEvent 3 ACTION_UP" + event.getKeyCode() );
            return false;
        }
        return super.dispatchKeyEvent(event);
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        DEBUG(" onKeyUp " +  keyCode);
        return super.onKeyUp(keyCode, event);
    }</pre><br>
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log信息：

D/ testMainActivity (  711):   dispatchKeyEvent 1 key = 23 event =  0
D/ testMainActivity (  711):   dispatchKeyEvent 2 ACTION_DOWN23

D/ testMainActivity (  711):   dispatchKeyEvent 1 key = 23 event =  1
D/ testMainActivity (  711):   dispatchKeyEvent 3 ACTION_UP23

Android系统按键操作最先是在dispatchKeyEvent中进行处理的，然后才是onKeyDown(int keyCode, KeyEvent event)和onKeyUp(int keyCode, KeyEvent event)。