c# httpclient 帮助类

以下是一个C#中使用HttpClient的帮助类，包含了常用的HTTP请求方法和一些常见的配置选项：

using System;
using System.Net.Http;
using System.Threading.Tasks;

public static class HttpClientHelper
{
    private static readonly HttpClient _httpClient = new HttpClient();

    public static async Task<string> GetAsync(string url)
    {
        var response = await _httpClient.GetAsync(url);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsStringAsync();
    }

    public static async Task<byte[]> GetByteArrayAsync(string url)
    {
        var response = await _httpClient.GetAsync(url);        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsByteArrayAsync();
    }

    public static async Task<string> PostAsync(string url, HttpContent content)
    {
        var response = await _httpClient.PostAsync(url, content);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsStringAsync();
    }

    public static async Task<byte[]> PostByteArrayAsync(string url, HttpContent content)
    {
        var response = await _httpClient.PostAsync(url, content);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsByteArrayAsync();
    }

    public static async Task<string> PutAsync(string url, HttpContent content)
    {
        var response = await _httpClient.PutAsync(url, content);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsStringAsync();
    }

    public static async Task<byte[]> PutByteArrayAsync(string url, HttpContent content)
    {
        var response = await _httpClient.PutAsync(url, content);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsByteArrayAsync();
    }

    public static async Task<string> DeleteAsync(string url)
    {
        var response = await _httpClient.DeleteAsync(url);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsStringAsync();
    }

    public static async Task<byte[]> DeleteByteArrayAsync(string url)
    {
        var response = await _httpClient.DeleteAsync(url);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadAsByteArrayAsync();
    }

    public static void SetTimeout(TimeSpan timeout)
    {
        _httpClient.Timeout = timeout;
    }

    public static void SetBaseAddress(string baseAddress)
    {
        _httpClient.BaseAddress = new Uri(baseAddress);
    }

    public static void SetDefaultRequestHeaders(Action<HttpRequestHeaders> action)
    {
        action(_httpClient.DefaultRequestHeaders);
    }
}

使用示例：

// 设置基地址
HttpClientHelper.SetBaseAddress("http://localhost:9000/");

// 设置超时时间
HttpClientHelper.SetTimeout(TimeSpan.FromSeconds(10));

// 设置默认请求头
HttpClientHelper.SetDefaultRequestHeaders(headers =>
{
    headers.Add("User-Agent", "HttpClientHelper");
});

// 发送GET请求
var response = await HttpClientHelper.GetAsync("index.html");
var content = await response.Content.ReadAsStringAsync();

// 发送POST请求
var content = new StringContent("Hello, world!");
var response = await HttpClientHelper.PostAsync("api/values", content);
var result = await response.Content.ReadAsStringAsync();