C# 使用HttpWebrequest将文件传输到php scipt（多部分/表单数据）

我在通过POST将文件发送到php脚本时遇到问题

我想模拟一个使用多部分/表单数据的表单，将POST数据发送到我的PHP脚本

form.php:

<form enctype="multipart/form-data" action="csvimport.php" method="POST">
<input type="hidden" name="MAX_FILE_SIZE" value="30000">
CSV-File: <input name="userfile" type="file">
Database: <select name="db">
     <option value="db1" selected>Db1</option>
     <option value="db2">Db2</option>
     <option value="db3">Db3</option>
     </select>
Passkey: <input name="passkey" type="password">
<input type="submit" value="Send File" class="UploadFormSubmitButton"></form>

$uploadfile = basename($_FILES['userfile']['name']); 
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile))
{ echo "UPLOAD SUCCESFULL"; }
else { echo "UPLOAD FAIL"; }

我正在使用以下代码：

public static void HttpUploadFile(string url, string file, string paramName, string contentType, NameValueCollection nvc)
    {
        string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
        byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");

        HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
        wr.ContentType = "multipart/form-data; boundary=" + boundary;
        wr.Method = "POST";
        wr.KeepAlive = true;
        wr.Credentials = System.Net.CredentialCache.DefaultCredentials;

        Stream rs = wr.GetRequestStream();

        string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}";
        foreach (string key in nvc.Keys)
        {
            rs.Write(boundarybytes, 0, boundarybytes.Length);
            string formitem = string.Format(formdataTemplate, key, nvc[key]);
            byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem);
            rs.Write(formitembytes, 0, formitembytes.Length);
        }
        rs.Write(boundarybytes, 0, boundarybytes.Length);

        string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";
        string header = string.Format(headerTemplate, paramName, file, contentType);
        byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);
        rs.Write(headerbytes, 0, headerbytes.Length);

        FileStream fileStream = new FileStream(file, FileMode.Open, FileAccess.Read);
        byte[] buffer = new byte[4096];
        int bytesRead = 0;
        while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
        {
            rs.Write(buffer, 0, bytesRead);
        }
        fileStream.Close();

        byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
        rs.Write(trailer, 0, trailer.Length);
        rs.Close();

        WebResponse wresp = null;
        try
        {
            wresp = wr.GetResponse();
            Stream stream2 = wresp.GetResponseStream();
            StreamReader reader2 = new StreamReader(stream2);

            MessageBox.Show(reader2.ReadToEnd()); //***!!SAYS UPLOAD FAILS!!***
        }
        catch (Exception ex)
        {
            //log.Error("Error uploading file", ex);
            if (wresp != null)
            {
                wresp.Close();
                wresp = null;
            }
        }
        finally
        {
            wr = null;
        }
    }

并调用函数：

Database db = new Database();
        NameValueCollection nvc = new NameValueCollection(); 
        nvc.Add("passkey", "123");
        nvc.Add("db", "db1");
        nvc.Add("MAX_FILE_SIZE", "30000");
        db.sendCSV("http://.../csvimport.php", "C:\\Users\\Ivo\\Documents\\FILEtoUPLOAD.csv", "file", "text/comma-separated-values", nvc);

问题代码：

<form enctype="multipart/form-data" action="csvimport.php" method="POST">
<input type="hidden" name="MAX_FILE_SIZE" value="30000">
CSV-File: <input name="userfile" type="file">
Database: <select name="db">
     <option value="db1" selected>Db1</option>
     <option value="db2">Db2</option>
     <option value="db3">Db3</option>
     </select>
Passkey: <input name="passkey" type="password">
<input type="submit" value="Send File" class="UploadFormSubmitButton"></form>

$uploadfile = basename($_FILES['userfile']['name']); 
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile))
{ echo "UPLOAD SUCCESFULL"; }
else { echo "UPLOAD FAIL"; }

->我可以读取所有post变量，但当我使用Web请求时，“$\u文件['userfile']['name']”和“$\u文件['userfile']['tmp\u name']”为空

当我上传Html表单上的文件时，我有一个类似“FILEtoUPLOAD.csv”的东西和一个路径。。有没有办法解决这个问题