ASP.NET Core-修改请求和返回的Body

修改请求的Body：

//这里ReadToEnd执行完毕后requestBodyStream流的位置会从0到最后位置(即request.ContentLength)            
            var RequestBody = new StreamReader(HttpContext.Request.BodyReader.AsStream()).ReadToEnd();//读取body
            byte[] content1 = Encoding.UTF8.GetBytes(RequestBody.Replace("ceo", "CEO"));//替换字符串并且字符串转换成字节

            var requestBodyStream = new MemoryStream();//创建一个流 
            requestBodyStream.Seek(0, SeekOrigin.Begin);//设置从0开始读取
            requestBodyStream.Write(content1, 0, content1.Length);//把修改写入流中
            HttpContext.Request.Body = requestBodyStream;//把修改后的内容赋值给请求body
            HttpContext.Request.Body.Seek(0, SeekOrigin.Begin);

修改返回的Body：

var orgBodyStream = context.Response.BodyWriter.AsStream();//获取body内容
            var ms = new MemoryStream();
            ms.Seek(0, SeekOrigin.Begin);
            using (var sr = new StreamReader(ms))//
            {
                string newContent = sr.ReadToEnd();
                if (newContent.Contains("ceo"))
                {
                    byte[] content = Encoding.UTF8.GetBytes(newContent.Replace("ceo", "CEO"));
                    ms.Write(content, 0, content.Length);
                    ms.Seek(0, SeekOrigin.Begin);
                }
                await ms.CopyToAsync(orgBodyStream);
            }

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