在项目中碰到这样的问题： 

由于系统中的按键在底层做了重新定义或者新增了按键，此时需要在APP层对按键事件（keyevent）做分解处理，模拟Android系统做法，把keyevent分解成： 

1、单击事件：就是普通key的单击； 

2、双击事件：500ms内同一按键单击两次； 

3、长按事件：同一按键长按超过1000ms（系统中长按事件为500ms）； 

4、组合按键：两个以上按键同时按住； 

其中的keyevent可以来自Activity、View子类的dispatchKeyEvent方法，也可以是我们自定义的接口，也可以是我们发广播送上来的，根据项目需求； 

关于各事件的原理： 

1、双击事件：每次点击的up事件中启动一个定时（500ms）线程消息，用Handler.postDelayed()方法。 

2、长按事件：每次点击的down事件中启动一个定时（1000ms）线程消息，用Handler.postDelayed()方法，注意：在RepeatCount==0时启动； 

3、组合按键：用变量记录每个按键的状态，再进行判断； 

具体代码如下： Java代码

package com.jerome.util;import android.content.Context;import android.os.Handler;import android.util.Log;import android.view.KeyEvent;public class KeyUtil {	private boolean isVolumeDown = false;	private boolean isVolumeUp = false;	private boolean isMenu = false;	private int currentKeyCode = 0;	private static Boolean isDoubleClick = false;	private static Boolean isLongClick = false;	CheckForLongPress mPendingCheckForLongPress = null;	CheckForDoublePress mPendingCheckForDoublePress = null;	Handler mHandler = new Handler();	Context mContext = null;	private String TAG = "";	public KeyUtil(Context context, String tag) {		mContext = context;		TAG = tag;	}	public void dispatchKeyEvent(KeyEvent event) {		int keycode = event.getKeyCode();		// 有不同按键按下，取消长按、短按的判断		if (currentKeyCode != keycode) {			removeLongPressCallback();			isDoubleClick = false;		}		// 处理长按、单击、双击按键		if (event.getAction() == KeyEvent.ACTION_DOWN) {			checkForLongClick(event);		} else if (event.getAction() == KeyEvent.ACTION_UP) {			checkForDoubleClick(event);		}		if (keycode == KeyEvent.KEYCODE_VOLUME_DOWN) {			if (event.getAction() == KeyEvent.ACTION_DOWN) {				isVolumeDown = true;			} else if (event.getAction() == KeyEvent.ACTION_UP) {				isVolumeDown = false;			}		} else if (keycode == KeyEvent.KEYCODE_VOLUME_UP) {			if (event.getAction() == KeyEvent.ACTION_DOWN) {				isVolumeUp = true;			} else if (event.getAction() == KeyEvent.ACTION_UP) {				isVolumeUp = false;			}		} else if (keycode == KeyEvent.KEYCODE_MENU) {			if (event.getAction() == KeyEvent.ACTION_DOWN) {				isMenu = true;			} else if (event.getAction() == KeyEvent.ACTION_UP) {				isMenu = true;			}		}		// 判断组合按键		if (isVolumeDown				&& isVolumeUp				&& isMenu				&& (keycode == KeyEvent.KEYCODE_VOLUME_UP						|| keycode == KeyEvent.KEYCODE_VOLUME_DOWN || keycode == KeyEvent.KEYCODE_MENU)				&& event.getAction() == KeyEvent.ACTION_DOWN) {			//组合按键事件处理；			isVolumeDown = false;			isVolumeUp = false;			isMenu = false;		}	}	private void removeLongPressCallback() {		if (mPendingCheckForLongPress != null) {			mHandler.removeCallbacks(mPendingCheckForLongPress);		}	}	private void checkForLongClick(KeyEvent event) {		int count = event.getRepeatCount();		int keycode = event.getKeyCode();		if (count == 0) {			currentKeyCode = keycode;		} else {			return;		}		if (mPendingCheckForLongPress == null) {			mPendingCheckForLongPress = new CheckForLongPress();		}		mPendingCheckForLongPress.setKeycode(event.getKeyCode());		mHandler.postDelayed(mPendingCheckForLongPress, 1000);	}	class CheckForLongPress implements Runnable {		int currentKeycode = 0;		public void run() {			isLongClick = true;			longPress(currentKeycode);		}		public void setKeycode(int keycode) {			currentKeycode = keycode;		}	}	private void longPress(int keycode) {		Log.i(TAG, "--longPress 长按事件--" + keycode);	}	private void singleClick(int keycode) {		Log.i(TAG, "--singleClick 单击事件--" + keycode);	}	private void doublePress(int keycode) {		Log.i(TAG, "---doublePress 双击事件--" + keycode);	}	private void checkForDoubleClick(KeyEvent event) {		// 有长按时间发生，则不处理单击、双击事件		removeLongPressCallback();		if (isLongClick) {			isLongClick = false;			return;		}		if (!isDoubleClick) {			isDoubleClick = true;			if (mPendingCheckForDoublePress == null) {				mPendingCheckForDoublePress = new CheckForDoublePress();			}			mPendingCheckForDoublePress.setKeycode(event.getKeyCode());			mHandler.postDelayed(mPendingCheckForDoublePress, 500);		} else {			// 500ms内两次单击，触发双击			isDoubleClick = false;			doublePress(event.getKeyCode());		}	}	class CheckForDoublePress implements Runnable {		int currentKeycode = 0;		public void run() {			if (isDoubleClick) {				singleClick(currentKeycode);			}			isDoubleClick = false;		}		public void setKeycode(int keycode) {			currentKeycode = keycode;		}	}	private void removeDoublePressCallback() {		if (mPendingCheckForDoublePress != null) {			mHandler.removeCallbacks(mPendingCheckForDoublePress);		}	}}

　　注意： 

只有Action Down状态下RepeatCount才会>0，避免长按和单击事件混淆；