Question

我有此代码：

else if (number == 5)
        {
            Console.Write("Student's index: ");
            int index1 = int.Parse(Console.ReadLine());
            try
            {
                customDataList.FindStudent(index1); //displays the element that has the specified index
            }
            catch (ArgumentOutOfRangeException)
            {
                Console.WriteLine("Please choose an index from 0 to 9!");
            }
        }

当用户不输入任何字符或输入非整数字符时，我需要使用try-catch处理错误。怎么办？

Answer 1

使用TryParse检查输入是否为整数。然后，如果它是整数，则对索引执行任何操作。

else if (number == 5)
{
    Console.Write("Student's index: ");
    var success = int.TryParse(Console.ReadLine(), out int index1);
    if (success)
    {
        //next logic here if the input is an integer
        try
        {
            customDataList.FindStudent(index1); //displays the element that has the specified index
        }
        catch (ArgumentOutOfRangeException)
        {
            Console.WriteLine("Please choose an index from 0 to 9!");
        }
    }
    else
    {
        //do something when the input is not an integer
    }
}

Answer 2

您需要将int.Parse行移到try {}块内。只有这样，它才会处于结构化异常处理的安全网中。然后，您可以针对FormatException see Int32.Parse docs for exceptions thrown.

添加第二个catch {}块

else if (number == 5)
{
    Console.Write("Student's index: ");

    try
    {
        int index1 = int.Parse(Console.ReadLine());
        customDataList.FindStudent(index1); //displays the element that has the specified index
    }
    catch (ArgumentOutOfRangeException)
    {
        Console.WriteLine("Please choose an index from 0 to 9!");
    }
    catch (FormatException)
    {
        Console.WriteLine("Error: Index must be a number.");
    }
}

C＃-如何使用try-catch块处理此代码中的错误？

2 个答案: