C# 引数パーサ

readme.md

C#引数パーサ

こんな感じで引数クラス作って

public class MyProgramArgument
{
    [Argument(name: "-file")]
    public string FileName { get; set; }

    [Argument(name: "-o")]
    public string OutFileName { get; set; }

    [Argument(name: "--over-write")]
    public bool IsOverWrite { get; set; }

    [Argument(name: "-process-count")]
    public int ProcessCount { get; set; }
}

こんな感じでパースする

public class Program
{
    public static void Main(string[] args)
    {
      var arg = Argument.Parse<MyProgramArgument>(args);
    }
}

適当に実行する

C:\---\Desktop> app.exe -file "C:\---\a.txt" -o "C:\---\a.out" -process-count 3 --over-write

Argument.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

public class Argument
{
    public static T Parse<T>(string[] args)
    {
        object obj = Activator.CreateInstance<T>();
        var props =
            typeof(T).GetProperties()
            .Where(x => null != x.GetCustomAttribute<ArgumentAttribute>())
            .ToDictionary(x => x.GetCustomAttribute<ArgumentAttribute>().Name, x => x);

        IList<string> unknownArgs = new List<string>();
        for (int i = 0; i < args.Length; i++)
        {
            string arg = args[i].ToLower();

            if (props.TryGetValue(arg, out PropertyInfo prop))
            {
                var attr = prop.GetCustomAttribute<ArgumentAttribute>();
                if (attr.IsMark && prop.PropertyType == typeof(bool))
                {
                    prop.SetValue(obj, true);
                }
                else
                {
                    if (prop.PropertyType == typeof(string))
                    {
                        if (args[i + 1].StartsWith("-"))
                        {
                            throw new ArgumentException($"Not found {arg} parameter value.");
                        }
                        else
                        {
                            prop.SetValue(obj, args[i + 1]);
                        }
                    }
                    else if (prop.PropertyType == typeof(bool))
                    {
                        prop.SetValue(obj, true);
                    }
                    else if (null != prop.PropertyType.GetMethod("TryParse"))
                    {
                        var tryParse = prop.PropertyType.GetMethod("TryParse", BindingFlags.Static);
                        var parameter = new object[] { args[i + 1], null, };
                        if ((bool)tryParse.Invoke(null, parameter))
                        {
                            prop.SetValue(obj, parameter[1]);
                        }
                        else
                        {
                            throw new ArgumentException($"Not found {arg} parameter value.");
                        }
                    }
                    else
                    {
                        throw new InvalidProgramException($"{prop.PropertyType} is unknown parameter type.");
                    }
                }
            }
        }

        return (T)obj;
    }
}

ArgumentAttribute.cs

using System;

public class ArgumentAttribute : Attribute
{
    public string Name { get; set; } = string.Empty;
    public bool IsMark { get; set; } = false;

    public ArgumentAttribute(string name = "")
    {
        Name = name;
    }
}