在 C# 中，是否可以重构我的 Post 和 Put 方法以消除代码重复？

Question

我有以下两种方法：

        private string Post(string url, ByteArrayContent content, AuthenticationToken token = null) {
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            using HttpClient client = new HttpClient();
            if (token != null) {
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token.Access_token);
            }

            return client.PostAsync(url, content)
                .Result.Content.ReadAsStringAsync()
                .Result;
        }

        private string Put(string url,  ByteArrayContent content,  AuthenticationToken token) {
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            using HttpClient client = new HttpClient();
            if (token != null) {
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token.Access_token);
            }

            return client.PutAsync(url, content)
                .Result.Content.ReadAsStringAsync()
                .Result;
        }

如您所见，唯一的区别是一个方法调用PostAsync，而另一个方法调用PutAsync。

是否可以编写一个函数，例如：

        private string Send(string url,  ByteArrayContent content,  AuthenticationToken token, String functionName) {
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            using HttpClient client = new HttpClient();
            if (token != null) {
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token.Access_token);
            }

            return client[sendFunction](url, content)
                .Result.Content.ReadAsStringAsync()
                .Result;
        }

然后我就可以将其他每个功能变成一个衬里，例如：

private string Post(string url, ByteArrayContent content, AuthenticationToken token = null) {
    this.Send(url, content, token, "PostAsync");
}

...如果我能以一种类型安全的方式传递函数或函数名，那就更好了。

Answer 1

您可以使用switch 表达式。它在 C#8 中变得出奇地实用。您可以在此处阅读更多内容并找到示例：

https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-8#switch-expressions

更新：考虑使用枚举而不是函数名来使您的代码类型安全。

Answer 2

进一步研究 Selvin 的回应，我想出了：

        private string Post(string url, ByteArrayContent content, AuthenticationToken token = null) {
            return this.Send(token, (client) => client.PostAsync(url, content));
        }

        private string Put(string url,  StringContent content,  AuthenticationToken token) {
            return this.Send(token, (client) => client.PutAsync(url, content));
        }

        private string Send(AuthenticationToken token,  Func<HttpClient, Task<HttpResponseMessage>> sendFunction) {
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            using HttpClient client = new HttpClient();
            if (token != null) {
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token.Access_token);
            }

            return sendFunction(client)
                .Result.Content.ReadAsStringAsync()
                .Result;
        }

...这几乎是我想要的，但我仍然需要表达两次“客户”。

C# 是否有任何符号可以让我删除这种冗余？

或者我应该接受它“尽可能好”？

Answer 3

我假设由于某种原因您不能使用 async/await 运算符，

您可以像这样减少冗余：

    public static class Ext
    {
        public static string Finalize(this Task<HttpResponseMessage> httpResponseMessage)
        {
            return httpResponseMessage
                .Result
                .Content
                .ReadAsStringAsync()
                .Result;
        }
    }

    public class Program
    {
        private string Post(string url, ByteArrayContent content, AuthenticationToken token = null)
        {
            return this.CreateClient(token)
                .PutAsync(url, content)
                .Finalize();
        }

        private string Put(string url, StringContent content, AuthenticationToken token)
        {
            return this.CreateClient(token)
                .PostAsync(url, content)
                .Finalize();
        }

        private HttpClient CreateClient(AuthenticationToken token)
        {

            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            using HttpClient client = new HttpClient();
            if (token != null)
            {
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token.Value);
            }

            return client;
        }
    }

因此，将客户端创建包装在一种方法中，并将 Finalizing 你的异步内容包装到扩展方法中