在 .Net 5 的中间件中读取请求正文

Question

我正在尝试读取从客户端发送到我的后端的请求正文。内容以 JSON 格式发送，并让用户从表单输入。如何在我为控制器路由设置的中间件中读取请求主体。

这是我的模型

namespace ChatboxApi.Models
{
    public class User
    {
        public string Login { get; set; } = default;
        public string Password { get; set; } = default;
        public string Email { get; set; } = default;
        public string FullName { get; set; } = default;
        public int Phone { get; set; } = default;
        public string Website { get; set; } = default;

    }
}

这是我的控制器

namespace ChatboxApi.Controllers
{
    [ApiController]
    [Route("api/signup")]
    public class SignupController : ControllerBase
    {
        [HttpPost]
        public ActionResult SignUp([FromBody] User user)
        {
            return Ok(user);
        }

    }
}

这是我的中间件class

namespace ChatboxApi.Middleware
{
    public class CreateSession
    {
        private readonly RequestDelegate _next;

        public CreateSession(RequestDelegate next)
        {
            this._next = next;
        }

        public async Task Invoke(HttpContext httpContext)
        {
           //I want to get the request body here and if possible
           //map it to my user model and use the user model here.
            
            
        }

}

Answer 1

通常Request.Body不支持倒带，只能读一次。临时解决方法是在调用 EnableBuffering 后立即拉出正文，然后将流倒回 0 并且不处理它：

public class CreateSession
{
    private readonly RequestDelegate _next;

    public CreateSession(RequestDelegate next)
    {
        this._next = next;
    }

    public async Task Invoke(HttpContext httpContext)
    {
        var request = httpContext.Request;

        request.EnableBuffering();
        var buffer = new byte[Convert.ToInt32(request.ContentLength)];
        await request.Body.ReadAsync(buffer, 0, buffer.Length);
        //get body string here...
        var requestContent = Encoding.UTF8.GetString(buffer);

        request.Body.Position = 0;  //rewinding the stream to 0
        await _next(httpContext);

    }
}

注册服务：

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    //...
    app.UseHttpsRedirection();

    app.UseMiddleware<CreateSession>();

    app.UseRouting();

    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllers();
    });

}

Answer 2

我创建了中间件来记录每个请求并保存在数据库中。希望这段代码对你有帮助。

using Newtonsoft.Json;

namespace ChatboxApi.Middleware
{
    public class CreateSession
    {
        private readonly RequestDelegate _next;    

        public CreateSession(RequestDelegate next)
        {
            this._next = next;
        }
           
        public async Task Invoke(HttpContext httpContext)
        {
           // I want to get the request body here and if possible
           // map it to my user model and use the user model here.

            var req = httpContext.Request;
            var xbody = await ReadBodyAsync(req);
            var bodyRaw = JsonConvert.SerializeObject(xbody);

            var param = JsonConvert.SerializeObject(req.Query);
            var header = JsonConvert.SerializeObject(req.Headers);
            var originalUrl = JsonConvert.SerializeObject(req.Path);
        }
}

在 .Net 5 的中间件中读取请求正文

Reading request body in middleware for .Net 5

.net

c#

asp.net

asp.net-mvc

asp.net-core-middleware