WinForm中文件上传服务器：HttpWebRequest

因项目需要，要实现WinForm下的文件上传，个人觉得采用FTP方法太麻烦，还得配置FTP服务器，要通过防火墙也是一个麻烦。本来打算采用WebClient方法，但是采用这个方法实现后，进度条很短时间后就达到最大值，要等待一段时间才能传送完毕，要是文件太大（我这里测试约100M），会出现错误。后来才知道，原来WebClient是在加载完整个文件到内存后才真正开始上传，怪不得会出现前面的问题了。不得已参考了很多文章，老外的一个文章对我启发很大（http://blogs.msdn.com/johan/archive/2006/11/15/are-you-getting-outofmemoryexceptions-when-uploading-large-files.aspx），是采用HttpWebRequest方法实现的。废话少说，开始进入正题。实现过程如下：

在WinForm里面调用下面的方法来上传文件：



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:/test.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。

/// <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>

public int UploadFile(string address, string fileNamePath, string saveName, ProgressBarControl 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("\r\n--" + strBoundary + "\r\n");

//请求头部信息

StringBuilder sb = new StringBuilder();

sb.Append("--");

sb.Append(strBoundary);

sb.Append("\r\nContent-Disposition: form-data; name=\"file\"; filename=\"");

sb.Append(saveName);

sb.Append("\"\r\nContent-Type: ");

sb.Append("application/octet-stream");

sb.Append("\r\n\r\n");

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.Properties.Maximum = int.MaxValue;

progressBar.Properties.Minimum = 0;

progressBar.EditValue = 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);

using (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);////文件的内容

offset += size;

progressBar.EditValue = (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";

System.Windows.Forms.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;

}

调用：

/// <summary>

/// HttpWebRequest上传

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void btnUpload_Click(object sender, EventArgs e)

{

try

{

string iniPath = DataConvert.ToString(btnOpenDialog.EditValue);

if (iniPath.Length == 0)

{

XtraMessageBox.Show("请选择要上传的文件！");

return;

}

panelJD.Visible = true;

string address = string.Format("{0}Save.aspx", Core.CoreOption.WsAddressErp);

int rst = UploadFile(address, iniPath, "dd.rar", progressBarControl1);

}

catch (Exception err)

{

XtraMessageBox.Show(err.Message);

}

}

aspx文件：

protected void Page_Load(object sender, EventArgs e)

{

// 在此处放置用户代码以初始化页面

try

{

if (Request.Files.Count > 0)

{

foreach (string f in Request.Files.AllKeys)

{

HttpPostedFile file = Request.Files[f];

string filePath = @"D:\Temp\" + file.FileName;

//string p= this.MapPath("test") + "//" + file.FileName;

file.SaveAs(filePath);

Response.Write("Success/r/n");

}

}

}

catch

{

Response.Write("Error/r/n");

}

}

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。