c# post文件参数到服务器

[czs06815394]

以下代码传递除文件形式的参数不行，别的类型的参数均是ok的，能够正确拿到服务器返回的信息，
public static string GetResponse(string url, string param, string method)
{
string reStr = "";
if (method.ToUpper() == "GET")
{
url = url + "?" + param;
}
HttpWebRequest hwrq = (HttpWebRequest)WebRequest.Create(url);
hwrq.Method = method.ToUpper();
hwrq.KeepAlive = true;
if (method.ToUpper() == "POST")
{
ServicePointManager.Expect100Continue = false;
hwrq.ContentType = "application/x-www-form-urlencoded";
byte[] bs = Encoding.UTF8.GetBytes(param);
hwrq.ContentLength = bs.Length;
using (Stream reqStream = hwrq.GetRequestStream())
{
reqStream.Write(bs, 0, bs.Length);
}
}
hwrq.Timeout = 50000;
using (HttpWebResponse hwrp = (HttpWebResponse)hwrq.GetResponse())
{
while (hwrp.StatusCode != HttpStatusCode.OK)
{
System.Threading.Thread.Sleep(500);
}
Stream st = hwrp.GetResponseStream();
reStr = new StreamReader(st, Encoding.UTF8).ReadToEnd();
st.Close();
st.Dispose();
}
return reStr;
}

那么我现在要传递一个文件类型的参数给服务器（如图片类型），应该怎么实现呢（用上面的犯方法不能正确得到返回数据）？？？

[czs06815394]

顶啊。。。。。。。。。。

[Jxb_Sir]

http://bbs.yiwowang.com/forum.php?mod=viewthread&tid=596

[willhuo]

正常的提交表单 hwrq.ContentType = "application/x-www-form-urlencoded"; 文件上传因为是二进制的数据上传到服务器，contenttype需要换成multipart

[以专业开发人员为伍]

传一个文件，使用一句

new WebClient().UploadFile(....)

[宝_爸]

HttpWebRequest的话，参考这个讨论中的代码:
Upload files with HTTPWebrequest (multipart/form-data)
http://stackoverflow.com/questions/566462/upload-files-with-httpwebrequest-multipart-form-data