在不使用fiddler的情况下,将httpwebrequest作为getresponse之前的字符串查看

如何在调用GetResponse方法之前将httpWebRequest对象视为字符串?我想看到请求的原始格式,比如在fiddler中:

Content-Type: multipart/form-data; boundary=---------------------------2600251021003 
Content-Length: 338 
-----------------------------2600251021003 Content-Disposition: form-data; name="UPLOAD_FILEName"; filename="Searchlight062210 w price.csv" Content-Type: application/vnd.ms-excel 
,,,,, 
-----------------------------2600251021003 
Content-Disposition: form-data; name="submit" 
submit 
-----------------------------2600251021003-- 

我尝试了遵循代码,但没有成功,因为流不可读。

 string GetRequestString(HttpWebRequest req)
        {
            Stream stream2 = req.GetRequestStream(); 
            StreamReader reader2 = new StreamReader(stream2);
            return reader2.ReadToEnd();  

        }