小程序抛出 IndexOutOfRangeException

Question

I am getting an error when running the above code and don't know the exact issue. What is the solution for this?

using System;

class second
{
    static void Main(string[] args)
    {
        Console.WriteLine("Hello, {}!", args[0]);
        Console.WriteLine("Welcome to the C# station tutorial!");

        Console.ReadLine();
    }
}

The error is "Index out of range" .

Answer 1

你缺少参数位置

Console.WriteLine("Hello,{0}!", args[0]); 

Answer 2

The string[] args parameter is the command-line parameters to the exe. I'm guessing that you didn't pass any arguments, therefore args[0] is out of range , just like it said. If you ran your exe as:

your.exe MyName

then it would have at least got past the IndexOutOfRangeException - to raise a FormatException instead ;p To fix that, change the {} to {0} .

Answer 3

This is what worked for me. Check to make sure that there are parameters. If not, provide feedback on the console.

        if (args.Length == 0)
        {
            Console.WriteLine("No input parameters were received.");
            return;
        }

Answer 4

I believe you ran the program off Visual Studio and thus had run the program without passing in any parameter against arg[] .

To pass in a parameter Eg Scott to arg[] ,

1. go to the Solution Explorer (menu View → Solution Explorer )

2. select Properties .

3. Input "Scott" into the "Command Line arguments" textbox under the Start Options section.

   The program will run as normal. See the image below.

Answer 5

If args has zero items, then attempting to get the first index of it (ie 0) will cause an index out of bounds exception. You should check that args isn't null or empty before attempting to reference an index within it. If you ran that example with some command line arguments it would probably work.