Winform中下载文件

////// 下载文件//////下载文件地址

///下载后的存放地址

///用于显示的进度条

public void  DownloadFile(string URL,string filename,System.Windows.Forms.ProgressBar prog)

{

  try

    { 

      System.Net.HttpWebRequestMyrq=(System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(URL);

      System.Net.HttpWebResponsemyrp=(System.Net.HttpWebResponse)Myrq.GetResponse();

      longtotalBytes=myrp.ContentLength;

      if(prog!=null)

        {

          prog.Maximum=(int)totalBytes;

        }

      System.IO.Stream st=myrp.GetResponseStream();

      System.IO.Stream so=new System.IO.FileStream(filename,System.IO.FileMode.Create);

      long totalDownloadedByte=0;

      byte[] by=new byte[1024];

int osize=st.Read(by,0, (int)by.Length);

while(osize>0)

{

totalDownloadedByte=osize+totalDownloadedByte;

System.Windows.Forms.Application.DoEvents();

so.Write(by,0,osize);

if(prog!=null)

{

prog.Value=(int)totalDownloadedByte;

}

osize=st.Read(by,0, (int)by.Length);

}

so.Close();

st.Close();

}

catch(System.Exception)

{

throw;

}

}