C#在WinForm下使用HttpWebRequest上傳文件並顯示進度

/// <summary>
/// 將本地文件上傳到指定的服務器(HttpWebRequest方法)
/// </summary>
/// <param name="address">文件上傳到的服務器</param>
/// <param name="fileNamePath">要上傳的本地文件（全路徑）</param>
/// <param name="saveName">文件上傳後的名稱</param>
/// <param name="progressBar">上傳進度條</param>
/// <returns>成功返回1，失敗返回0</returns>
private int Upload_Request(string address, string fileNamePath, string saveName, ProgressBar progressBar)
{
int returnValue = 0;

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

//時間戳
string strBoundary = "----------" + DateTime.Now.Ticks.ToString("x");
byte[] boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + strBoundary + "\r\n");

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

// 根據uri創建HttpWebRequest對象
HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(new Uri(address));
httpReq.Method = "POST";

//對發送的數據不使用緩存
httpReq.AllowWriteStreamBuffering = false;

//設置獲得響應的超時時間（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;

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

//已上傳的字節數
long offset = 0;

//開始上傳時間
DateTime startTime = DateTime.Now;
int size = r.Read(buffer, 0, bufferLength);
Stream postStream = httpReq.GetRequestStream();

//發送請求頭部消息
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 = "已用時：" + 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 = " 正在連接…";
}
lblState.Text = "已上傳：" + (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);
}
//添加尾部的時間戳
postStream.Write(boundaryBytes, 0, boundaryBytes.Length);
postStream.Close();

//獲取服務器端的響應
WebResponse webRespon = httpReq.GetResponse();
Stream s = webRespon.GetResponseStream();
StreamReader sr = new StreamReader(s);

//讀取服務器端返回的消息
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;
}

參數說明如下：

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

fileNamePath：要上傳的本地文件，如：D:\test.rar

saveName：文件上傳到服務器後的名稱，如：200901011234.rar

progressBar：顯示文件上傳進度的進度條。

接收文件的WebForm添加一個Save.aspx頁面，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\r\n");
}
catch
{
Response.Write("Error\r\n");
}
}
}

同時需要配置WebConfig文件的httpRuntime 如下：

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

不能的話最大只能上傳4M了。要是想上傳更大的文件，maxRequestLength，executionTimeout設置大些，同時WinForm下的代碼行

//設置獲得響應的超時時間（300秒）
httpReq.Timeout = 300000;

也要修改，另外別忘了看看IIS的連接超時是否設置為足夠大。