C#请求WebApi接口常用的两种方式

一、WebRequest方式引用dll

using System.IO;
using System.Net;
using System.Threading.Tasks;
//Post
public static string HttpPost(string url, string body)
{
    Encoding encoding = Encoding.UTF8;
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
    request.Method = "POST";
    request.Accept = "text/html, application/xhtml+xml, */*";
    request.ContentType = "application/json";
    byte[] buffer = encoding.GetBytes(body);
    request.ContentLength = buffer.Length;
    request.GetRequestStream().Write(buffer, 0, buffer.Length);
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
    {
        return reader.ReadToEnd();
    }
}
//GET
public static string HttpGet(string url)
{
    Encoding encoding = Encoding.UTF8;
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
    request.Method = "GET";
    request.Accept = "text/html, application/xhtml+xml, */*";
    request.ContentType = "application/json";
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
    {
        return reader.ReadToEnd();
    }
}

WebRequest 核心概念与实现解析

WebRequest 是网络编程中用于处理HTTP/HTTPS请求的核心机制，其在不同开发环境和编程语言中存在多种实现形式。以下是主要分类及技术要点：

• WebRequest 的核心功能

  • HTTP请求处理
  • WebRequest 主要用于构建HTTP请求报文（包含请求行、请求头和请求体），并在服务端解析后存储于Request对象中，便于后续参数获取及业务处理。同时，通过Response对象设置响应数据，由服务器按HTTP协议格式返回客户端。
  • 请求生命周期管理

  • 包括建立连接、处理重定向、超时控制等。例如，C#的HttpWebRequest支持设置

    AllowAutoRedirect

    控制重定向，

    Timeout

    设定超时限制。

二、HttpClient 方式

static HttpClient client = new HttpClient();
//根据 ID 获取产品
static async Task CreateProductAsync(Product product)
{
    HttpResponseMessage response = await client.PostAsJsonAsync(
    "api/products", product);
    response.EnsureSuccessStatusCode();
    // return URI of the created resource.
    return response.Headers.Location;
}
//创建新产品
static async Task GetProductAsync(string path)
{
    Product product = null;
    HttpResponseMessage response = await client.GetAsync(path);
    if (response.IsSuccessStatusCode)
    {
        product = await response.Content.ReadAsAsync();
    }
    return product;
}
//更新产品
static async Task UpdateProductAsync(Product product)
{
    HttpResponseMessage response = await client.PutAsJsonAsync(
    $"api/products/{product.Id}", product);
    response.EnsureSuccessStatusCode();
    // Deserialize the updated product from the response body.
    product = await response.Content.ReadAsAsync();
    return product;
}
//删除产品
static async Task DeleteProductAsync(string id)
{
    HttpResponseMessage response = await client.DeleteAsync(
    $"api/products/{id}");
    return response.StatusCode;
}

HttpClient 异步调用

static async Task RunAsync()
{
    client.BaseAddress = new Uri("http://localhost:64195/");
    client.DefaultRequestHeaders.Accept.Clear();
    client.DefaultRequestHeaders.Accept.Add(
    new MediaTypeWithQualityHeaderValue("application/json"));
    try
    {
        Product product = new Product
        {
            Name = "Gizmo",
            Price = 100,
            Category = "Widgets"
        };
        var url = await CreateProductAsync(product);
        Console.WriteLine($"Created at {url}");
        // Get the product
        product = await GetProductAsync(url.PathAndQuery);
        ShowProduct(product);
        // Update the product
        Console.WriteLine("Updating price...");
        product.Price = 80;
        await UpdateProductAsync(product);
        // Get the updated product
        product = await GetProductAsync(url.PathAndQuery);
        ShowProduct(product);
        // Delete the product
        var statusCode = await DeleteProductAsync(product.Id);
        Console.WriteLine($"Deleted (HTTP Status = {(int)statusCode})");
    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message);
    }
    Console.ReadLine();
}

C# HttpClient 核心功能与使用指南

HttpClient 是 .NET 中用于发送 HTTP 请求和接收响应的现代化工具，支持高性能、异步操作及灵活的配置。以下是其关键特性与使用要点：

• 核心特性

  • 异步支持

  • 所有方法均原生支持

    async/await

    ，适用于高并发场景（如微服务通信）。示例：

    var response = await client.GetAsync("https://api.example.com/data");

  • 连接池管理

  • 每个

    HttpClient

    实例维护独立的连接池，复用 TCP 连接以提升性能。

  • 注意：避免频繁创建实例，推荐通过单例或

    IHttpClientFactory

    管理。

  • 请求配置

  • 支持自定义请求头、超时时间、认证方式（如 Basic、JWT、Cookie）。示例（设置请求头）：

    client.DefaultRequestHeaders.Authorization =   new AuthenticationHeaderValue("Bearer", "your_jwt_token");

  • 数据传输格式

  • 支持 JSON、表单、文件上传等格式，需通过

    StringContent

    、

    MultipartFormDataContent

    等类封装数据。

原文转载自：https://mp.weixin.qq.com/s/t7IffcgbGlBiIO-rl88DFg