c# - 如果我在启动文件中添加中间件。那个时候在模型中没有得到请求

Question

这个中间件在启动文件中添加。

app.UseMiddleware<RequestResponseLoggingMiddleware>();

中间件是

public class RequestResponseLoggingMiddleware
{
    private readonly RequestDelegate _next;

    public RequestResponseLoggingMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task Invoke(HttpContext context)
    {
        //First, get the incoming request
        var request = await FormatRequest(context.Request);

        //Copy a pointer to the original response body stream
        var originalBodyStream = context.Response.Body;

        //Create a new memory stream...
        using (var responseBody = new MemoryStream())
        {
            //...and use that for the temporary response body
            context.Response.Body = responseBody;

            //Continue down the Middleware pipeline, eventually returning to this class
            await _next(context);

            //Format the response from the server
            var response = await FormatResponse(context.Response);

            //TODO: Save log to chosen datastore

            //Copy the contents of the new memory stream (which contains the response) to the original stream, which is then returned to the client.
            await responseBody.CopyToAsync(originalBodyStream);
        }
    }

    private async Task<string> FormatRequest(HttpRequest request)
    {
        var body = request.Body;

        //This line allows us to set the reader for the request back at the beginning of its stream.
        request.EnableRewind();

        //We now need to read the request stream.  First, we create a new byte[] with the same length as the request stream...
        var buffer = new byte[Convert.ToInt32(request.ContentLength)];

        //...Then we copy the entire request stream into the new buffer.
        await request.Body.ReadAsync(buffer, 0, buffer.Length);

        //We convert the byte[] into a string using UTF8 encoding...
        var bodyAsText = Encoding.UTF8.GetString(buffer);

        //..and finally, assign the read body back to the request body, which is allowed because of EnableRewind()
        request.Body = body;

        return $"{request.Scheme} {request.Host}{request.Path} {request.QueryString} {bodyAsText}";
    }

    private async Task<string> FormatResponse(HttpResponse response)
    {
        //We need to read the response stream from the beginning...
        response.Body.Seek(0, SeekOrigin.Begin);

        //...and copy it into a string
        string text = await new StreamReader(response.Body).ReadToEndAsync();

        //We need to reset the reader for the response so that the client can read it.
        response.Body.Seek(0, SeekOrigin.Begin);

        //Return the string for the response, including the status code (e.g. 200, 404, 401, etc.)
        return $"{response.StatusCode}: {text}";
    }
}

使用此中间件获取请求，但随后不在原始模型类中传递该请求。

这个中间件添加在启动文件中。当时就面临这个问题。

因此，在传入模型类之前获取请求的任何其他方式。我还需要获得无效请求.. 因为我需要将其插入到与日志相同的数据库中。

Answer 1

您的FormatRequest 中存在一些问题，请尝试应用以下更改:

1.交换var body = request.Body;和request.EnableRewind();的顺序

2.在request.Body = body;之前插入body.Seek(0, SeekOrigin.Begin);

最终代码:

private async Task<string> FormatRequest(HttpRequest request)
    {
        //This line allows us to set the reader for the request back at the beginning of its stream.
        request.EnableRewind();

        var body = request.Body;

        //We now need to read the request stream.  First, we create a new byte[] with the same length as the request stream...
        var buffer = new byte[Convert.ToInt32(request.ContentLength)];

        //...Then we copy the entire request stream into the new buffer.
        await request.Body.ReadAsync(buffer, 0, buffer.Length);

        //We convert the byte[] into a string using UTF8 encoding...
        var bodyAsText = Encoding.UTF8.GetString(buffer);

        body.Seek(0, SeekOrigin.Begin);
        //..and finally, assign the read body back to the request body, which is allowed because of EnableRewind()
        request.Body = body;

        return $"{request.Scheme} {request.Host}{request.Path} {request.QueryString} {bodyAsText}";
    }