Asp. NET file upload Download (2) Go

ASP. NET upload, download file

2011-01-08 16:21:48|  Category:. NET | Tags: | Report | Font size Big medium small subscription

First we want to determine whether the user chooses to upload the file, we can use the following sentence to achieve:

if (file1.postedfile.contentlength>0)

If the user has uploaded files, then:

String name = File1.PostedFile.FileName;//Gets the input file name

int i= name. LastIndexOf (".");

String NewName =name. Substring (i);//Gets the file name extension

Change the "c:\\" below to the address you want to save.

DateTime Now=datetime.now;

String Strname=now. Year.tostring () +now. Month.tostring () +now. Day.tostring () +file1.postedfile.contentlength.tostring () +newname;//renames the file. The name is: Year + month + day + file size.

Common ways to download files in ASP (GO)

1. Stream mode download     protected void Button4_Click (object sender, EventArgs e)     {        string filename = "Aaa.txt";//client-saved file name   & nbsp;     string filePath = Server.MapPath ("Download/aaa.txt");//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 Response.AddHeader ("Content-disposition", "attachment;         Filename= "+ httputility.urlencode (FileName, System.Text.Encoding.UTF8));         Response.BinaryWrite (bytes);         Response.Flush (); Response.End ();

}

2.WriteFile chunked download protected void button3_click (object sender, EventArgs e) {

string filename = "Aaa.txt";//client-saved file name string FilePath = Server.MapPath ("Download/aaa.txt");//path

System.IO.FileInfo FileInfo = new System.IO.FileInfo (FilePath);

if (fileinfo.exists = = true) {Const LONG ChunkSize = 102400;//100k reads the file every time, only 100K is read, 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;// Get 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));//The size of the read                 Response.OutputStream.Write (buffer, 0, lengthread);                 Response.Flush ();                 Datalengthtoread = Datalengthtoread-lengthread;            }              Response.close ();        }    }

3.WriteFile implementation download protected void button2_click (object sender, EventArgs e) {/* using System.IO; */

string filename = "Asd.txt";//client-saved file name string FilePath = Server.MapPath ("Download/aaa.txt");//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 ();    }

   4.TransmitFile Implementation download          protected void Button1_click1 ( Object sender, EventArgs e)         {            /*              Microsoft provides a new approach to response objects TransmitFile to address the use of Response.BinaryWrite               downloading more than 400MB files causes the Aspnet_wp.exe process to recycle without successfully downloading the issue. The              code is as follows:               */            String strFileName = "Three idle device management system operating manual iems.ppt";             Response.ContentType = "application/ X-zip-compressed ";            //response.contentencoding = System.teXt. Encoding.GetEncoding ("gb2312");             string filename = BLL. Config.part_em_upload_doc + strFileName;

Bll. Config.part_em_upload_doc is the path ("d:/emuploaddoc/") Response.AddHeader ("Content-disposition", "Attachment;fil Ename= "+server.urlpathencode (strFileName));

server.urlpathencode () resolves the file name garbled problem.         Response.TransmitFile (filename); }

Upload a File instance:

if (Fileupload.PostedFile.ContentLength > 0)    //Determine if the user uploaded the file                  {                     String strFileName = fileupload.postedfile.filename; //Get upload path and file name                      int i = strFileName. IndexOf (".");

   //if (! System.IO.Directory.Exists (path)) directory.createdirectory (path); Determine if there are no uploaded directories and create this directory                      string strnewname = strFileName. Substring (i); Gets the extension of the uploaded file                      datetime dttime = new DateTime ();                      string struploadname = Fileupload.filename; Get file names for uploaded files                     //string struploadname = DateTime.Now.ToString ("Yyyymmddhhmmss")                     //              + Fileupload.postedfilE.contentlength.tostring () + strnewname;  //rename the file. Name: Year + month + day + file size                      String Path = Server.MapPath ("~/fileupload/receptiondatabase/");  //Get server folder                      String FileURL = path + "\ \" + Struploadname;                      Fileupload.PostedFile.SaveAs (FileURL);   //upload file to server                      Resources. UploadFile = struploadname;  //attachment file name

}

Download the file instance:

The using System.IO is referenced first;

if (!string. IsNullOrEmpty (this. FileName)//To determine if there is an attachment, read the attachment name from the repository filename to indicate the attachment name {string filename = this.                 FileName;                 string filepath = "~/fileupload/receptiondatabase/" + filename;  String path = Server.MapPath (filepath); Get file path

                FileStream fs = new FileStream (path, FileMode.Open);                 byte[] bytes = new byte[ (int) fs. Length];                 FS. Read (bytes, 0, bytes. Length);                 FS. Close ();                 Response.ContentType = "Application/octet-stream";                //Notification browser download file is not open file                 Response.AddHeader (" Content-disposition "," attachment; Filename= "+ httputility.urlencode (filename, System.Text.Encoding.UTF8));                 response.transmitfile (path);                 Response.BinaryWrite (bytes);                 Response.Flush ();                 Response.End ();

      //test can not download software (thunderbolt, etc.) Download parts             }             else             {                 this. Clientscriptalert ("This item has no attachments!") ");            }              this. FileName = "";