Android 判断当前程序是否在前台运行

/**
     * Android 判断当前程序是否在前台运行 
     * 需要添加android.permission.GET_TASKS权限
     * @param packageName 
     * @return
     */
    private boolean isTopActivity(String packageName) {
		System.out.println("**********************top packageName:" + packageName);
		ActivityManager activityManager = (ActivityManager) this.getSystemService(Context.ACTIVITY_SERVICE);
		List tasksInfo = activityManager.getRunningTasks(1);
		if (tasksInfo.size() > 0) {
			System.out.println("*********************curr packageName:" + tasksInfo.get(0).topActivity.getPackageName());
			// 应用程序位于堆栈的顶层
			if (packageName.equals(tasksInfo.get(0).topActivity.getPackageName())) {
				return true;
			}
		}
		return false;
	}