如何在asp net core 2.2中间件中多次读取请求正文？

Question

我试过这个： 读取请求正文两次 ，这个：https : //github.com/aspnet/Mvc/issues/4962 但没有用。我这样阅读请求正文：

app.Use(async (context, next) =>
{
    var requestBody = await ReadStream(context.Request.Body);
    var requestPath = context.Request.Path.ToString();
    //Do some thing

    await next.Invoke();

    var responseStatusCode = context.Response.StatusCode;
    //Do some other thing
});

private async Task<string> ReadStream(Stream stream)
{
    using (var streamReader = new StreamReader(stream))
    {
        var result = await streamReader.ReadToEndAsync();

        return result;
    }
}

在控制器中，我得到“处置对象”或“空流”。

Answer 1

.netcore 3.1 版本的@HoussamNasser 上面的回答。我创建了一个可重用的函数来读取请求正文。请注意更改：HttpRequestRewindExtensions.EnableBuffering(request)。EnableBuffering 现在是HttpRequestRewindExtensions类的一部分。

public async Task<JObject> GetRequestBodyAsync(HttpRequest request)
    {
        JObject objRequestBody = new JObject();

        // IMPORTANT: Ensure the requestBody can be read multiple times.
        HttpRequestRewindExtensions.EnableBuffering(request);

        // IMPORTANT: Leave the body open so the next middleware can read it.
        using (StreamReader reader = new StreamReader(
            request.Body,
            Encoding.UTF8,
            detectEncodingFromByteOrderMarks: false,
            leaveOpen: true))
        {
            string strRequestBody = await reader.ReadToEndAsync();
            objRequestBody = SerializerExtensions.Deserialize<JObject>(strRequestBody);

            // IMPORTANT: Reset the request body stream position so the next middleware can read it
            request.Body.Position = 0;
        }

        return objRequestBody;
    }

此函数将返回一个 JObject，可用于读取 Request Body 对象的属性。SerializerExtensions 是我用于序列化和反序列化的自定义扩展。

在中间件中，您可以注入IHttpContextAccessor httpContextAccessor构造函数。然后像HttpRequest request = _httpContextAccessor.HttpContext.Request;. 最后，可以调用可重用的函数，如GetRequestBodyAsync(request)

Answer 2

经过一番努力并使用“context.Request.EnableRewind()”，它终于像这样工作了：

app.Use(async (context, next) =>
{
    context.Request.EnableRewind();
    var stream = context.Request.Body;

    using (var reader = new StreamReader(stream))
    {
        var requestBodyAsString = await reader.ReadToEndAsync();

        if (stream.CanSeek)
            stream.Seek(0, SeekOrigin.Begin);

        //Do some thing

        await next.Invoke();

        var responseStatusCode = context.Response.StatusCode;
        //Do some other thing
    }
});