ASP.NET中下载文件的几种实例代码

  

复制代码 代码如下:

  //TransmitFile实现下载

  protected void Button1_Click(object sender, EventArgs e)

  {

  /*

  微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite

  下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。

  代码如下:

  */

  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实现下载

  protected void Button2_Click(object sender, EventArgs e)

  {

  /*

  using System.IO;

  */

  string fileName = "asd.txt";//客户端保存的文件名

  string filePath = Server.MapPath("DownLoad/aaa.txt");//路径

  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分块下载

  protected void Button3_Click(object sender, EventArgs e)

  {

  string fileName = "aaa.txt";//客户端保存的文件名

  string filePath = Server.MapPath("DownLoad/aaa.txt");//路径

  System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);

  if (fileInfo.Exists == true)

  {

  const long ChunkSize = 102400;//100K 每次读取文件,只读取100K,这样可以缓解服务器的压力

  byte[] buffer = new byte[ChunkSize];

  Response.Clear();

  System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);

  long dataLengthToRead = iStream.Length;//获取下载的文件总大小

  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));//读取的大小

  Response.OutputStream.Write(buffer, 0, lengthRead);

  Response.Flush();

  dataLengthToRead = dataLengthToRead - lengthRead;

  }

  Response.Close();

  }

  }

  //流方式下载

  protected void Button4_Click(object sender, EventArgs e)

  {

  string fileName = "aaa.txt";//客户端保存的文件名

  string filePath = Server.MapPath("DownLoad/aaa.txt");//路径

  //以字符流的形式下载文件

  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";

  //通知浏览器下载文件而不是打开

  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");

  //'文件名称

  WebForm.Response.AddHeader("content-disposition", "attachment; filename='"+System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8)+"'");

  WebForm.Response.ContentType = "Application/octet-stream";

  //'文件内容

  WebForm.Response.Write(FileBody);//-----------

  WebForm.Response.End();

  }

  //上面这段代码是下载一个动态产生的文本文件,若这个文件已经存在于服务器端的实体路径,则可以通过下面的函数:

  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");

  //文件名称

  WebForm.Response.AddHeader("content-disposition", "attachment; filename='" + System.Web.HttpUtility.UrlEncode(FileNameWhenUserDownload, System.Text.Encoding.UTF8) +"'" );

  WebForm.Response.ContentType = "Application/octet-stream";

  //文件内容

  WebForm.Response.Write(System.IO.File.ReadAllBytes(FilePath));//---------

  WebForm.Response.End();

  }

  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

  --保存文档

  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;

  --打开文档

  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);

  }

  }

  }