C#如何捕捉字母字符

Question

我目前正在开发一个高度转换计算器，将英尺和英寸转换为厘米，并希望创建一个“catch”，当用户输入字母字符而不是数字字符时，它会产生一条错误消息，甚至可能是一个 catch将地址是用户输入无效(例如输入 5' 111' 而不是 5' 11')。

当前捕获不起作用:

    Console.Clear();
    Console.WriteLine("Convert your height into Centimeters!");
    Console.WriteLine("Please give your height in the form of Feet and Inches, for example: 5'10\"");
    //user enters 5'10"
    heightString = Console.ReadLine();
    //heightString = "5'10""
    heightString = heightString.Remove(heightString.Length - 1);
    //heightString = "5'10"
    posOfInch = heightString.IndexOf("'");
    //posOfInch = 1

            try
            {
            }

            catch ()
            {
                throw new ("Generic Error Message");                    
            }

//此捕获在应用程序中无效

    feet = Convert.ToInt16(heightString.Remove(posOfInch));
    //feet = 5
    inches = Convert.ToInt16(heightString.Substring(posOfInch + 1));
    //inches = 10

    inches = (feet * 12) + inches;
    centimetres = (inches * 2.54);

    Console.WriteLine("Your height is " + centimetres + "cm");
    //Console.WriteLine("Please give your height measurement in inches : ");
    //calculating = int.Parse(Console.ReadLine());
    //inches(calculating);
    Console.ReadKey();
    return true;

关于我如何挑战这个捕获问题有什么建议吗？

Answer 1

无需捕获任何异常，使用TryParse:

string heightString = "5'10";

short feet, inches;
bool validFormat = false;
int index = heightString.IndexOf("'", StringComparison.Ordinal);

if (index >= 0)
    validFormat = short.TryParse(heightString.Remove(index), out feet)
               && short.TryParse(heightString.Substring(index + 1), out inches);

顺便说一句，因为你没有在任何地方转换，所以捕获 InvalidCastException 是没有意义的。