C# 一个命令行库：McMaster.Extensions.CommandLineUtils

首先在要被执行的 类型 加上参数：

        [Option(Description = "CloudEvents 'source' (default: urn:example-com:mysource:abc)", LongName = "source", ShortName = "s")]
        private string Source { get; } = "urn:example-com:mysource:abc";

        [Option(Description = "CloudEvents 'type' (default: com.example.myevent)", LongName = "type", ShortName = "t")]
        private string Type { get; } = "com.example.myevent";

        [Required,Option(Description = "HTTP(S) address to send the event to", LongName = "url", ShortName = "u"),]
        private Uri Url { get; }

可以加上模型验证规则，例如 Required 表示次参数是必填的。

例如，参数 url，命令行输入：

--url=xxx
--url xxx

被执行的类型，需要定义一个 OnExecuteAsync 方法。

        private async Task OnExecuteAsync()
        {
            var cloudEvent = new CloudEvent
            {
                Id = Guid.NewGuid().ToString(),
                Type = Type,
                Source = new Uri(Source),
                DataContentType = MediaTypeNames.Application.Json,
                Data = JsonConvert.SerializeObject("hey there!")
            };

            var content = cloudEvent.ToHttpContent(ContentMode.Structured, new JsonEventFormatter());

            var httpClient = new HttpClient();
            // Your application remains in charge of adding any further headers or 
            // other information required to authenticate/authorize or otherwise
            // dispatch the call at the server.
            var result = await httpClient.PostAsync(Url, content);

            Console.WriteLine(result.StatusCode);
        }

执行：

        public static int Main(string[] args)
        {
            var result =  CommandLineApplication.Execute<MyProgram>(args);
            return 0;
        }