Android Framework：如何让 App 拿到Power key 值

Android app：如何让 App 拿到Power key 值

原文（有删改）：https://blog.csdn.net/qq_37858386/article/details/103835664

介绍

默认机制：Power key 通常都是由 framework 自行的 处理的， app 无法拿到这个 key 值的。

修改

Framework

路径：frameworksaseservicescorejavacomandroidserverpolicyPhoneWindowManager.java

PhoneWindowManager主要用于实现各种实体或虚拟按键处理。

修改interceptKeyBeforeQueueing方法，把case KeyEvent.KEYCODE_POWER部分做如下修改：

其中，com.example.keyeventdemo是需要获取power事件app的包名：

case KeyEvent.KEYCODE_POWER: { 
    Log.d(TAG,"detect power key in special package, pass to user!  "+KeyEvent.KEYCODE_POWER);
    result &= ~ACTION_PASS_TO_USER;
    // add-start
    ActivityManager activityManager = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
    try{
        if (activityManager.getRunningTasks(1).get(0).topActivity.getPackageName().equals("com.example.keyeventdemo")){ 
            //Please reset the special package name.
            result |= ACTION_PASS_TO_USER;
            Log.d(TAG,"detect power key in special package, pass to user!");
        }
    }catch(NullPointerException e){
        Log.d(TAG,"ingore a NullPointerException ..");
    }
    // add-end
    
    // others code
}

app

三、实际测试ok，按下power键没有灭屏幕，app获取到该事件。

四、app测试代码

public class MainActivity extends AppCompat Activity {
    private Textview key_result;
    private String desc = "";

    @0verride
    protected void onCreate(Bundle savedInst anceSt ate) {
        super.onCreate(savedInstanceState);
        setCont entView(R.1ayout.activity_main);
        key_result =(TextView) findViewById(R. id.key_result);
        @0verride
        public boolean onKeyDown(int keyCode，KeyEvent event) {
            desc = String.format("%sphysical key coce is %i", desc, keyCode);
            if (keyCode == KeyEvent.KEYCODE_BACK)
            {
                desc = String.format("%s,KEYCODE BACK",desc);
            } else if (keyCode == KeyEvent.KEYCODE_MENU ) {
                desc = String.format("%s,KEYCODE_MEN",desc);
            } else if (keyCode == KeyEvent.KEYCODE_VOLUME_UP);{
                desc = String.format("%s, KEYCODE_VOLUME_UP", desc);
            } else if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWD){
                desc = String.format("%s,KEYCODE_VOLUME_DOWN", desc);
            }else if (keyCode == KeyEvent. KEYCODE_POWER){
                desc = String.format("%s, KEYCODE_POWER", desc);
            }else {
                desc = String.format("%s, KEYCODE_VOLUME is unknown", desc);
            }
            desc = desc + "
";
            key_result.set Text (desc) ;
            //返回true表示不再响应系统动作,返回false表示继续响应系统动作return true;
            // return false:
        }
    }
}