c# - 防止 C# 由于无效用户输入而崩溃

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这个问题已经有答案了:

How do I prevent crashing from invalid user input? (3 个回答)

已关闭 7 年前。

C# 编码新手，学习该语言约 2 周。制作一款手机游戏的想法在我脑海中盘旋了一年多，我的决心之一就是今年学习编码。我正在阅读一本 C# 简介书籍，并掌握了基础知识后，我正在尝试编写基于老式文本的冒险游戏作为技能强化工具。我想这是一个由 3 部分组成的问题 1) 我正在尝试编写一个系统，其中用户为属性类型选择 1-10 之间的值，但无法弄清楚如果用户输入其他内容如何阻止程序崩溃比一个整数。 2) 我正在尝试编写一种方法，让游戏从原始属性值中减去已分配的属性值，以确保用户最终得到的属性值不会超过 25。 3) 我想在底部，如果用户不喜欢设置，则可以重新开始。下面是我的代码:

        Console.WriteLine("Now you must choose your basic attributes!. You have a total of 25 points to distribute over 5 core skills:");
        Console.WriteLine("Strength, Speed, Intelligence, Personality, and Ingenuity.");
        Console.WriteLine("Choose carefully! Values too high or too low may impact your ability to escape from the world!");
        int attributes = 25;
        int strength = -1;
        int speed = -1;
        int intelligence = -1;
        int personality = -1;
        int ingenuity = -1;
        Console.WriteLine("Attributes remaining: " + (attributes));
        do
        {

            Console.Write("Please choose a value for Strength (0-10): ");
            string strengthAsText = Console.ReadLine();
            strength = Convert.ToInt32(strengthAsText);
            if(strength > 10)
            {
                Console.WriteLine("You can't be that fast!");
            }
            else
            {
                Console.WriteLine("Good choice, please choose the next attribute.");
                attributes = 25 - strength;
                Console.WriteLine("Attributes remaining: " + (attributes));
            }
       }
        while (strength < 0 || strength > 10 && strength <= attributes);

        int attributes2 = (attributes - strength);
        do
        {

            Console.Write("Please choose a value for Speed (0-10): ");
            string speedAsText = Console.ReadLine();
            speed = Convert.ToInt32(speedAsText);
            if (speed > 10)
            {
                Console.WriteLine("You can't be that fast!");
            }
            else if (speed < attributes2)
            {
                Console.WriteLine("You do not have enough remaining attributes to be this fast. Please choose again.");
            }
            else
            {
                Console.WriteLine("Good choice, please choose the next attribute.");
                attributes2 = (attributes2 - speed);
                Console.WriteLine("Attributes remaining: " + (attributes2));
            }
        }
        while (speed < 0 || speed > 10 && speed <= attributes2);

        do
        {
            Console.Write("Please choose a value for Intelligence (0-10): ");
            string intelligenceAsText = Console.ReadLine();
            intelligence = Convert.ToInt32(intelligenceAsText);
            if (intelligence > 10)
            {
                Console.WriteLine("You can't be that smart!");
            }
            else
            {
                Console.WriteLine("Good choice, please choose the next attribute.");
                Console.WriteLine("Attributes remaining: " + (attributes - strength - speed - intelligence));
            }
        }
        while (intelligence < 0 || intelligence > 10 && intelligence <= attributes);

        do
        {
            Console.Write("Please choose a value for Personality (0-10): ");
            string personalityAsText = Console.ReadLine();
            personality = Convert.ToInt32(personalityAsText);
            if (personality > 10)
            {
                Console.WriteLine("You can't be that charismatic!");
            }
            else
            {
                Console.WriteLine("Good choice, please choose the next attribute.");
                Console.WriteLine("Attributes remaining: " + (attributes - strength - speed - intelligence - personality));
            }
        }
        while (personality < 0 || personality > 10 && personality <= attributes);

        do
        {
            Console.Write("Please choose a value for Ingenuity (0-10): ");
            string ingenuityAsText = Console.ReadLine();
            ingenuity = Convert.ToInt32(ingenuityAsText);
            if (ingenuity > 10)
            {
                Console.WriteLine("You can't be that creative!");
            }
            else
            {
                Console.WriteLine("Good choice, please choose the next attribute.");
                Console.WriteLine("Attributes remaining: " + (attributes - strength - speed - intelligence - personality - ingenuity));
            }
        }
        while (ingenuity < 0 || ingenuity > 10 && ingenuity <= attributes);

        Console.WriteLine("Congratulations, you have chosen wisely.");
        Console.WriteLine();
        Console.WriteLine("Your final attribute values are: ");
        Console.WriteLine();
        Console.WriteLine("Strength     " + (strength));
        Console.WriteLine("Speed        " + (speed));
        Console.WriteLine("Intelligence " + (intelligence));
        Console.WriteLine("Personaility " + (personality));
        Console.WriteLine("Ingenuity    " + (ingenuity));
        Console.WriteLine();
        Console.WriteLine("Please press any key to continue...");

        Console.ReadKey();
        Console.WriteLine("You begin you journey by awakening in a pile of what looks like starship debris.");
        Console.ReadKey();
    }
}

}

如果这很困惑，我深表歉意，就像我说的，我对此很陌生。谢谢大家的帮助!

Answer 1

1. 要在值不是 int 时阻止程序崩溃，请使用 TryParse 方法:

   bool result = Int32.TryParse(value,out number) //value is the input, number is the output
   If (result)
   {
       //value converted successfully 
   }
   else
   {
       //value failed to convert
   }
   

2. 无需创建第二个变量attributes2。只需使用第一个并继续递减即可。这将确保您可以跟踪总共 25 个属性。

3. 将您的例程包装在一个方法中，如果用户想像这样重新开始，则再次调用它:

   string s = Console.ReadLine();
   If (s == "start over")
   {
       StartOver(); //this method contains your whole routine
   }
   else
   {
       //exit the application or whatever you want done here
   }