带进度条的下载

 

 

public long DownloadFile(string FileURL, string FileSavePath)
        {
            long Filelength = 0;
            long ThisLength = 0;
            HttpWebRequest req = HttpWebRequest.Create(FileURL) as HttpWebRequest;
            req.Timeout = 10*1000;
            req.AllowAutoRedirect = true;
            label1.Text = "=> 正在检测 "+FileSavePath + "...";
            try
            {
                HttpWebResponse res = req.GetResponse() as HttpWebResponse;
                System.IO.Stream stream = res.GetResponseStream();            
                Filelength = res.ContentLength;
                progressBar1.Maximum = (int)Filelength;
                int allk = (int)(Filelength/1024);
                label1.Text = "=> 正在下载 "+FileSavePath + "...";
                byte[] b = new byte[1024]; 
                int nReadSize = 0;
                nReadSize = stream.Read(b, 0, 1024);                

                System.IO.FileStream fs = System.IO.File.Create(FileSavePath);
                try
                {
                    
                    while (nReadSize > 0)
                    {                                            
                        label1.Refresh();
                        progressBar1.Value += nReadSize; 
                        ThisLength += nReadSize;
                        label1.Text = "=> 正在下载 "+FileSavePath +"("+(int)(ThisLength/1024)+"K/"+allk+"K)";
                        fs.Write(b, 0, nReadSize);
                        nReadSize = stream.Read(b, 0, 1024);
                    }
                }                    
                finally
                {
                    fs.Close();
                }
                progressBar1.Value=0;
                progressBar1.Maximum = 0;
                label1.Text = "";
                res.Close();
                stream.Close();
            }
            catch (Exception er)
            {
                throw er;
            }        
            return Filelength;
        }