android判断当前应用程序处于前台还是后台

/**
     *判断当前应用程序处于前台还是后台
     *
     * @param context

* @return   
     */
    public static boolean isApplicationBroughtToBackground(final Context context) {
        ActivityManager am = (ActivityManager) context.getSystemService

(Context.ACTIVITY_SERVICE);
        List<RunningTaskInfo> tasks = am.getRunningTasks(1);
        if (!tasks.isEmpty()) {
            ComponentName topActivity = tasks.get(0).topActivity;
            if (!topActivity.getPackageName().equals(context.getPackageName())) {
                return true;
            }
        }
        return false;

}
上面这段代码是需要一个权限的：
<uses-permission android:name="android.permission.GET_TASKS" /> 
 
下面这段代码也可以判断，无需权限
 /**
 *
 * @param context
 * @return
 */
 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())) {
    if (appProcess.importance ==

RunningAppProcessInfo.IMPORTANCE_BACKGROUND) {
     Log.i(String.format("Background App:",
       appProcess.processName));
     return true;
    } else {
     Log.i(String.format("Foreground App:",
       appProcess.processName));
     return false;
    }
   }
  }
  return false;
 }