用moq模拟HttpMessageHandler -如何获取请求的内容？

// 引入所需的命名空间
using Moq;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;

// 创建HttpMessageHandler的模拟实例
var mockHandler = new Mock<HttpMessageHandler>();

// 设置模拟实例的处理逻辑
mockHandler.Protected()
    .Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>())
    .ReturnsAsync(new HttpResponseMessage() { StatusCode = HttpStatusCode.OK })
    .Callback<HttpRequestMessage, CancellationToken>((request, cancellationToken) =>
    {
        // 获取请求的内容
        var content = request.Content.ReadAsStringAsync().Result;
        // 对请求的内容进行处理
        // ...
    });

// 使用模拟实例创建HttpClient
var httpClient = new HttpClient(mockHandler.Object);

// 发送请求
var response = await httpClient.GetAsync("https://example.com");

// 处理响应
// ...