//TransmitFile download
    protected void Button1_Click(object sender, EventArgs e)
    {
        /*
         Microsoft is Response Object provides 1 A new approach TransmitFile To solve the use of Response.BinaryWrite
         Download over 400mb The file time result Aspnet_wp.exe A problem with a process recall that failed to download successfully.
         The code is as follows:
        */
        Response.ContentType = "application/x-zip-compressed";
        Response.AddHeader("Content-Disposition", "attachment;filename=z.zip");
        string filename = Server.MapPath("DownLoad/z.zip");
        Response.TransmitFile(filename);
    }
    //WriteFile download
    protected void Button2_Click(object sender, EventArgs e)
    {
        /*
        using System.IO;
        */
        string fileName = "asd.txt";// The file name saved by the client
        string filePath = Server.MapPath("DownLoad/aaa.txt");// The path
        FileInfo fileInfo = new FileInfo(filePath);
        Response.Clear();
        Response.ClearContent();
        Response.ClearHeaders();
        Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
        Response.AddHeader("Content-Length", fileInfo.Length.ToString());
        Response.AddHeader("Content-Transfer-Encoding", "binary");
        Response.ContentType = "application/octet-stream";
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
        Response.WriteFile(fileInfo.FullName);
        Response.Flush();
        Response.End();
    }
    //WriteFile Block download
    protected void Button3_Click(object sender, EventArgs e)
    {
        string fileName = "aaa.txt";// The file name saved by the client
        string filePath = Server.MapPath("DownLoad/aaa.txt");// The path
        System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
        if (fileInfo.Exists == true)
        {
            const long ChunkSize = 102400;//100K  Each time the file is read, only read 100K , which can relieve the pressure on the server
            byte[] buffer = new byte[ChunkSize];
            Response.Clear();
            System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);
            long dataLengthToRead = iStream.Length;// Gets the total size of the downloaded file
            Response.ContentType = "application/octet-stream";
            Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));
            while (dataLengthToRead > 0 && Response.IsClientConnected)
            {
                int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));// Read size
                Response.OutputStream.Write(buffer, 0, lengthRead);
                Response.Flush();
                dataLengthToRead = dataLengthToRead - lengthRead;
            }
            Response.Close();
        }
    }
    // Streaming download
    protected void Button4_Click(object sender, EventArgs e)
    {
        string fileName = "aaa.txt";// The file name saved by the client
        string filePath = Server.MapPath("DownLoad/aaa.txt");// The path
        // Download the file as a stream of characters
        FileStream fs = new FileStream(filePath, FileMode.Open);
        byte[] bytes = new byte[(int)fs.Length];
        fs.Read(bytes, 0, bytes.Length);
        fs.Close();
        Response.ContentType = "application/octet-stream";
        // Notifies the browser to download the file instead of opening it
        Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
        Response.BinaryWrite(bytes);
        Response.Flush();
        Response.End();
    }
//----------------------------------------------------------
public void DownloadFile( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FileBody )
{
　　WebForm.Response.ClearHeaders();
　　WebForm.Response.Clear();
　　WebForm.Response.Expires = 0;
　　WebForm.Response.Buffer = true;
　　WebForm.Response.AddHeader("Accept-Language", "zh-tw");
　　//' The file name
　　WebForm.Response.AddHeader("content-disposition", "attachment; filename='"+System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8)+"'");
　　WebForm.Response.ContentType = "Application/octet-stream";
　　//' The file content
　　WebForm.Response.Write(FileBody);//-----------
    WebForm.Response.End();
}

// The above code is for download 1 Four dynamically generated text files. If the file already exists in the entity path on the server side, the following functions can be used:
public void DownloadFileByFilePath( System.Web.UI.Page WebForm,String FileNameWhenUserDownload ,String FilePath )
{
　　WebForm.Response.ClearHeaders();
　　WebForm.Response.Clear();
　　WebForm.Response.Expires = 0;
    WebForm.Response.Buffer = true;
　　WebForm.Response.AddHeader("Accept-Language", "zh-tw");
　　// The file name
　　WebForm.Response.AddHeader("content-disposition", "attachment; filename='" + System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8) +"'" );
　　WebForm.Response.ContentType = "Application/octet-stream";
　　// The file content
　　WebForm.Response.Write(System.IO.File.ReadAllBytes(FilePath));//---------
　　WebForm.Response.End();
}
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-- Save the document
string docName, docExtended;
Stream doc = fuDoc.FileContent;
int docLength = fuDoc.PostedFile.ContentLength;
byte[] docData = new byte[docLength];
doc.Read(docData, 0, docLength);
docExtended = fuDoc.FileName.Substring(fuDoc.FileName.IndexOf("."));
if (string.IsNullOrEmpty(tbDoc.Text))
docName = fuDoc.FileName;
else
docName = tbDoc.Text + docExtended;
SafetyDocInfo data = new SafetyDocInfo(ddlSort.Text, docName, fuDoc.PostedFile.ContentType, docData);
SafetyDoc safety = new SafetyDoc();
safety.Insert(data);
tbDoc.Text = string.Empty;
 -- open the document
public void ViewSafetyDoc(string pDocSort, string pDocName)
{
OracleParameter[] parms = GetSafetyDocParm(SQL_View_SafetyDoc);
parms[0].Value = pDocSort;
parms[1].Value = pDocName;
using (OracleDataReader rdr = OracleHelper.ExecuteReader(OracleHelper.ConnectionString, CommandType.Text, SQL_View_SafetyDoc, parms))
{
while (rdr.Read())
{
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.Buffer = true;
HttpContext.Current.Response.Charset = "GB2312";
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
HttpContext.Current.Response.ContentType = rdr.GetString(1);
HttpContext.Current.Response.BinaryWrite((byte[])rdr["Doc"]);
string FileName = rdr.GetString(0);
FileName = System.Web.HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8);
HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + FileName);
}
}
}