在命令行中的参数后获取参数

Question

Hi so I am trying to get the two values after user input --dimensions.

For example when I do: dotnet app.dll --dimensions 1 2 (In command line)

It prints

1
2

Which is the result I'm after.

But when I do: dotnet app.dll --test --dimensions 1 2

It returns hi , meaning that --test worked. But returns an error for --dimensions

hi
Unhandled exception. System.FormatException: Input string was not in a correct format.
   at System.Number.ThrowOverflowOrFormatException(ParsingStatus status, TypeCode type)
   at System.String.System.IConvertible.ToInt32(IFormatProvider provider)
   at System.Convert.ToInt32(Object value)
   at MainClass.Main(String[] args)

I don't want the argument to only work if its the first argument given. That is why I added --test before --dimensions

I want it to work when the argument --dimensions is placed anywhere.

For example dotnet app.dll --test --test --dimensions 1 2 --test

Which should return

hi
hi
1
2
hi

Im new with this as well :( Sorry.

Code:

using System;

class MainClass
{
    private static int value1, value2;
    static void Main(string[] args)
    {
        foreach (string value in args)
        {
            int for_dimensions = 0;

            string testing = "--test";

            if (value == "--dimensions" && args.Length >= for_dimensions + 2)
            {
                object test1 = args.GetValue(for_dimensions+1);
                value1 = Convert.ToInt32(test1);
                    
                object test2 = args.GetValue(for_dimensions + 2);
                value2 = Convert.ToInt32(test2);

                Console.WriteLine(value1);
                Console.WriteLine(value2);
            }

            if (value == testing)
            {
                Console.WriteLine("hi");
            }
            
        }
        
    }
}

Thank you

Answer 1

If you don't want to use an existing command line parser framework (which I highly recommend due to higher flexibility) for example this one, you can achieve your desired output like this:

// Find array index of "--dimensions"
var argIndex = Array.IndexOf(args, "--dimensions");

// Get remaining array size (all items after "--dimensions")
var subArraySize = args.Length - argIndex - 1;
string[] subArray = new string[subArraySize];

// Put all remaining items (all items after "--dimensions") into new array
Array.Copy(args, argIndex + 1, subArray, 0, subArraySize);

// Iterate over all items after "--dimensions"
var results = new List<int>();
foreach(var entry in subArray)
{
    // Check if the item is another command, if so we are finished
    if(entry.StartsWith('-'))
        break;
    
    // Item isn't a command, try to parse it to int and if successful add to result set
    if(int.TryParse(entry, out var numEntry))
        results.Add(numEntry);
}

To output the found parameters for "--dimensions" just iterate over results :

foreach(var result in results)
{
    Console.WriteLine(result);
}

With this implementation you can process a variable amount of dimension inputs. Either like in your example 1 and 2, or just 1 or 1, 2 and 3 for example:

dotnet app.dll --test --test --dimensions 1 2 --test
dotnet app.dll --test --test --dimensions 1 --test
dotnet app.dll --test --test --dimensions 1 2 3 --test