Android 判断app是否在前台还是在后台运行

public static boolean isBackground(Context context) {
ActivityManager activityManager = (ActivityManager) context
.getSystemService(Context.ACTIVITY_SERVICE);
List<RunningAppProcessInfo> appProcesses = activityManager
.getRunningAppProcesses();
for (RunningAppProcessInfo appProcess : appProcesses) {
if (appProcess.processName.equals(context.getPackageName())) {
/*
BACKGROUND=400 EMPTY=500 FOREGROUND=100
GONE=1000 PERCEPTIBLE=130 SERVICE=300 ISIBLE=200
*/
Log.i(context.getPackageName(), "此appimportace ="
+ appProcess.importance
+ ",context.getClass().getName()="
+ context.getClass().getName());
if (appProcess.importance != RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
Log.i(context.getPackageName(), "处于后台"
+ appProcess.processName);
return true;
} else {
Log.i(context.getPackageName(), "处于前台"
+ appProcess.processName);
return false;
}
}
}
return false;
}