C#程序设计 A3.2 字母判断（Console）

public A32Page(){string str = "";while (true){Console.WriteLine("请输入5个大写字母：");str = Console.ReadLine();if (str.Length <= 5){Console.WriteLine("字符个数不是5个，请重新输入！");continue;}bool isValid = true;for (int i = 0; i < 5; i++){char c = str[i];if (c < 'A' || c > 'Z') {Console.WriteLine("第{0}个字符{1}不是大写字母，请重新输入:", i+1,c);isValid = false;break;}}if (!isValid) {Console.WriteLine();continue;}Console.WriteLine("输入的字符满足要求");break;}}