[转]C#在WinForm下使用HttpWebRequest上传文件并显示进度

/// <summary> 
/// 将本地文件上传到指定的服务器(HttpWebRequest方法) 
/// </summary> 
/// <param name="address">文件上传到的服务器</param> 
/// <param name="fileNamePath">要上传的本地文件（全路径）</param> 
/// <param name="saveName">文件上传后的名称</param> 
/// <param name="progressBar">上传进度条</param> 
/// <returns>成功返回1，失败返回0</returns> 
private int Upload_Request(string address, string fileNamePath, string saveName, ProgressBar progressBar) 
{ 
    int returnValue = 0;

 

    // 要上传的文件 
    FileStream fs = new FileStream(fileNamePath, FileMode.Open, FileAccess.Read); 
    BinaryReader r = new BinaryReader(fs);

 

    //时间戳 
    string strBoundary = "----------" + DateTime.Now.Ticks.ToString("x"); 
    byte[] boundaryBytes = Encoding.ASCII.GetBytes(" --" + strBoundary + " ");

 

    //请求头部信息 
    StringBuilder sb = new StringBuilder(); 
    sb.Append("--"); 
    sb.Append(strBoundary); 
    sb.Append(" "); 
    sb.Append("Content-Disposition: form-data; name=""); 
    sb.Append("file"); 
    sb.Append(""; filename=""); 
    sb.Append(saveName); 
    sb.Append("""); 
    sb.Append(" "); 
    sb.Append("Content-Type: "); 
    sb.Append("application/octet-stream"); 
    sb.Append(" "); 
    sb.Append(" "); 
    string strPostHeader = sb.ToString(); 
    byte[] postHeaderBytes = Encoding.UTF8.GetBytes(strPostHeader);

 

    // 根据uri创建HttpWebRequest对象 
    HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(new Uri(address)); 
    httpReq.Method = "POST";

 

    //对发送的数据不使用缓存 
    httpReq.AllowWriteStreamBuffering = false;

 

    //设置获得响应的超时时间（300秒） 
    httpReq.Timeout = 300000; 
    httpReq.ContentType = "multipart/form-data; boundary=" + strBoundary; 
    long length = fs.Length + postHeaderBytes.Length + boundaryBytes.Length; 
    long fileLength = fs.Length; 
    httpReq.ContentLength = length; 
    try 
    { 
        progressBar.Maximum = int.MaxValue; 
        progressBar.Minimum = 0; 
        progressBar.Value = 0;

 

        //每次上传4k 
        int bufferLength = 4096; 
        byte[] buffer = new byte[bufferLength];

 

        //已上传的字节数 
        long offset = 0;

 

        //开始上传时间 
        DateTime startTime = DateTime.Now; 
        int size = r.Read(buffer, 0, bufferLength); 
        Stream postStream = httpReq.GetRequestStream();

 

        //发送请求头部消息 
        postStream.Write(postHeaderBytes, 0, postHeaderBytes.Length); 
        while (size > 0) 
        { 
            postStream.Write(buffer, 0, size); 
            offset += size; 
            progressBar.Value = (int)(offset * (int.MaxValue / length)); 
            TimeSpan span = DateTime.Now - startTime; 
            double second = span.TotalSeconds; 
            lblTime.Text = "已用时：" + second.ToString("F2") + "秒"; 
            if (second > 0.001) 
            { 
                lblSpeed.Text = " 平均速度：" + (offset / 1024 / second).ToString("0.00") + "KB/秒"; 
            } 
            else 
            { 
                lblSpeed.Text = " 正在连接…"; 
            } 
            lblState.Text = "已上传：" + (offset * 100.0 / length).ToString("F2") + "%"; 
            lblSize.Text = (offset / 1048576.0).ToString("F2") + "M/" + (fileLength / 1048576.0).ToString("F2") + "M"; 
            Application.DoEvents(); 
            size = r.Read(buffer, 0, bufferLength); 
        } 
        //添加尾部的时间戳 
        postStream.Write(boundaryBytes, 0, boundaryBytes.Length); 
        postStream.Close();

 

        //获取服务器端的响应 
        WebResponse webRespon = httpReq.GetResponse(); 
        Stream s = webRespon.GetResponseStream(); 
        StreamReader sr = new StreamReader(s);

 

        //读取服务器端返回的消息 
        String sReturnString = sr.ReadLine(); 
        s.Close(); 
        sr.Close(); 
        if (sReturnString == "Success") 
        { 
            returnValue = 1; 
        } 
        else if (sReturnString == "Error") 
        { 
            returnValue = 0; 
        }

 

    } 
    catch 
    { 
        returnValue = 0; 
    } 
    finally 
    { 
        fs.Close(); 
        r.Close(); 
    }

 

    return returnValue; 
}

 

 

 

参数说明如下：

 

address：接收文件的URL地址，如：http://localhost/UploadFile/Save.aspx

 

fileNamePath：要上传的本地文件，如：D: est.rar

 

saveName：文件上传到服务器后的名称，如：200901011234.rar

 

progressBar：显示文件上传进度的进度条。

 

 

 

接收文件的WebForm添加一个Save.aspx页面，Load方法如下：

 

protected void Page_Load(object sender, EventArgs e) 
{ 
    if (Request.Files.Count > 0) 
    { 
        try 
        { 
            HttpPostedFile file = Request.Files[0]; 
            string filePath = this.MapPath("UploadDocument") + "\" + file.FileName; 
            file.SaveAs(filePath); 
            Response.Write("Success "); 
        } 
        catch 
        { 
            Response.Write("Error "); 
        } 
    }
}

 

同时需要配置WebConfig文件的httpRuntime 如下：

 

<httpRuntime maxRequestLength="102400" executionTimeout="300"/>

 

不能的话最大只能上传4M了。要是想上传更大的文件，maxRequestLength，executionTimeout设置大些，同时WinForm下的代码行

 

//设置获得响应的超时时间（300秒）
httpReq.Timeout = 300000;

 

也要修改，另外别忘了看看IIS的连接超时是否设置为足够大。

参考：

http://blogs.msdn.com/johan/archive/2006/11/15/are-you-getting-outofmemoryexceptions-when-uploading-large-files.aspx