Question

我目前正在设置我的方法，通过HTTP POST发送一些信息并获得响应。我将信息作为字符串发送到变量post_info中的函数。（例如："name=" & username & "&pass=" & password）。这有效，但我不知道如何像这样发送csv文件...＆＃34; name = user＆amp; pass = password＆amp; file = [myfile]＆＃34;。

Public Sub MyRequest(ByVal url As String, ByVal post_info As String, Optional SendingFile As Boolean = False)

    Dim req As HttpWebRequest
    Dim enc As UTF8Encoding
    Dim postdata As String
    Dim postdatabytes As Byte()

    req = HttpWebRequest.Create(url)
    enc = New System.Text.UTF8Encoding
    postdata = post_info
    postdatabytes = enc.GetBytes(postdata)
    req.Method = "POST"
    req.ContentType = "application/x-www-form-urlencoded"
    req.AllowWriteStreamBuffering = True
    req.ContentLength = postdatabytes.Length

    Using stream = req.GetRequestStream()
        stream.Write(postdatabytes, 0, postdatabytes.Length)
    End Using

    Using response As HttpWebResponse = req.GetResponse()
        Dim contentLength As Long = response.ContentLength
        Dim bytesReceived As Long = 0.0
        Dim bufferLength As Integer = 8192
        Dim buffer(bufferLength) As Char
        Dim sb As New StringBuilder

        Using reader As StreamReader = New StreamReader(response.GetResponseStream())
            Do
                Dim bufferedCount As Integer = reader.Read(buffer, 0, bufferLength)
                sb.Append(buffer, 0, bufferedCount)
                bytesReceived += bufferedCount
                Console.WriteLine(bytesReceived / contentLength * 100 & "%")
            Loop While bytesReceived < contentLength
        End Using

        json_response = JsonConvert.DeserializeObject(sb.ToString)

    End Using

End Sub

Answer 1

你有两个选择（第一个更容易，第二个更优雅）：

在CSV文件内容上使用HttpUtility.UrlEncode，并在请求正文中使用此值："name=user&pass=password&file=" + HttpUtility.UrlEncode(myfileContents)
使用专为此目的而设计的内容类型：multipart / form-data 。 http://tools.ietf.org/html/rfc2388

如何通过HTTP POST发送文件以及其他文本参数？

1 个答案: