得到手机当前显示的activity的名字

    /**

     * @return 手机当前的activity

     */

     String getRunningActivityName(){

        ActivityManager activityManager=(ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);

        String runningActivity=activityManager.getRunningTasks(1).get(0).topActivity.getClassName();

        return runningActivity;

    }