asp.net - 使用 webrequest 发布表单数据并上传文件

Question

我需要上传一个带有 webrequest 的文件，并将它与请求中的一些其他表单数据结合起来。今天我的帖子请求如下所示：

 Protected Function PostData(ByRef url As String, ByRef POST As String, ByRef Cookie As System.Net.CookieContainer) As String
    Dim request As HttpWebRequest
    Dim response As HttpWebResponse
    request = CType(WebRequest.Create(url), HttpWebRequest)
    request.ContentType = "application/x-www-form-urlencoded"
    request.ContentLength = POST.Length
    request.Method = "POST"
    request.AllowAutoRedirect = False

    Dim requestStream As Stream = request.GetRequestStream()
    Dim postBytes As Byte() = Encoding.ASCII.GetBytes(POST)
    requestStream.Write(postBytes, 0, postBytes.Length)
    requestStream.Close()
    response = CType(request.GetResponse, HttpWebResponse)
    Return New StreamReader(response.GetResponseStream()).ReadToEnd()
End Function

字符串 post（在 request.ContentLength 中）现在包含此表单数据：

"access_token=xxyyzzz"

现在我还想添加此表单数据参数：文件（要上传的 pdf 文件）收件人电子邮件（字符串值）收件人名称（字符串值）

我如何需要更改 PostData 函数才能在 webrequest 中发布文件和字符串数据？

感谢帮助！

彼得

标签： asp.netvb.net