在做应用层APP需求的过程中，HOME键的监听，Back键的监听，这都是很常见的问题，那你有试过，去拦截HOME键的事件吗，有去了解过如何处理吗，流程如何
首先大家应该先了解一种情况，就是Android在应用中是无法拦截Home键的，今天我们带大家看一下Home键的三种情况。
1、在应用中按下Home键的逻辑处理
xref: /frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java
这是源码的具体类跟地址
创建一个启动到桌面的Intent。
Intent mHomeIntent;mHomeIntent = new Intent(Intent.ACTION_MAIN, null);mHomeIntent.addCategory(Intent.CATEGORY_HOME);mHomeIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);startActivity(mHomeIntent);2、在应用中监听Home键
在Android应用中如果想监听Home键可以使用广播机制，这个在源码中也有体现。
这样就可以监听Home的是否被按下。
static public final String SYSTEM_DIALOG_KEY = "reason";static public final String SYSTEM_DIALOG_GLOBAL_ACTIONS = "globalactions";static public final String SYSTEM_DIALOG_RECENT_APPS = "recentapps";static public final String SYSTEM_DIALOG_HOME_KEY = "homekey";static public final String SYSTEM_DIALOG_ASSIST = "assist";@Overridepublic void onReceive(Context arg0, Intent arg1) {String action = arg1.getAction();//按下Home键会发送ACTION_CLOSE_SYSTEM_DIALOGS的广播if (action.equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) {String reason = arg1.getStringExtra(SYSTEM_DIALOG_KEY);if (reason != null) {if (reason.equals(SYSTEM_DIALOG_HOME_KEY)) {// 短按home键Toast.makeText(arg0, "短按Home键", Toast.LENGTH_SHORT).show();} else if (reason.equals(SYSTEM_DIALOG_RECENT_APPS)) {// RECENT_APPS键Toast.makeText(arg0, "RECENT_APPS", Toast.LENGTH_SHORT).show();}}}}
3、在Frameworks层拦截Home键
xref: /frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java
直接在onKeyDown中判断通过keyCode == KeyEvent.KEYCODE_HOME是不能拦截的
/** {@inheritDoc} */@Overridepublic long interceptKeyBeforeDispatching(WindowState win, KeyEvent event, int policyFlags) {
......
// First we always handle the home key here, so applications// can never break it, although if keyguard is on, we do let// it handle it, because that gives us the correct 5 second// timeout.if (keyCode == KeyEvent.KEYCODE_HOME) {// If we have released the home key, and didn't do anything else// while it was pressed, then it is time to go home!if (!down) {//添加的判断当前前台运行APP代码if (!isBackgroundActivity(mContext, PKG_NAME_xxxxx)) {Log.d(TAG, "xxxx app is foreground");if (!getTopActivity(mContext).equals(ACTIVITY_NAME_xxxx)) { Log.d(TAG, "xxxxx app is foreground activity");return -1;}return -1;}cancelPreloadRecentApps();mHomePressed = false;if (mHomeConsumed) {mHomeConsumed = false;return -1;}......
