Asp.net: Two Methods for uploading files

1. Inner type (runat Server Mode)

This method is currently used by most people. The event-driven method is used to upload files. Form and file field must be set to runat server.

The Code is as follows:

Void button1_click (Object source, eventargs e ){

If (file1.postedfile! = NULL ){

// Obtain the upload file type //
String filetype = file1.postedfile. contenttype. tostring ();

// Check whether upload is allowed. Currently, only jpg and GIF files can be uploaded //
If (filetype = "image/pjpeg" | filetype = "image/GIF ")
{
// Get the file name //
String filename = file1.postedfile. filename. tostring ();

// Get the extension //
String fileext = filename. substring (filename. lastindexof ("."));

// Reset the file name //
Datetime now = datetime. now;
String frontfilename = now. tofiletimeutc () + file1.postedfile. contentlength. tostring ();
Filename = "/upload/" + frontfilename + fileext;

Try {
// Save the file
File1.postedfile. saveas (server. mappath (filename ));
Response. Write ("uploaded successfully ");

}
Catch (exception exc ){
Response. Write ("Upload error, cause: +" exc. tostring ()"");
}

}
}

<Form enctype = "multipart/form-Data" runat = "server">
Select the file to be uploaded <input id = "file1" type = file runat = "server">
<Input type = button id = "button1" value = "click to start uploading" onserverclick = "button#click" runat = "server">
</Form>

The reason for this is that the implementation method must be completed in the same aspx file, which has certain restrictions, but is highly secure.

2. Open Mode (submit form Mode)

This method can be submitted by other pages with high freedom. The Code is as follows:

Upload. aspx

<Form name = "form1" Action = "Save. aspx" method = "Post" enctype = "multipart/form-Data">
<Input type = "file" id = "file1" name = "file1">
<Input type = "Submit" name = "Submit" value = "save">
</Form>

Save. aspx

Private void page_load (Object sender, system. eventargs E)
{
If (request. Files. Count = 0 ){
Response. Write ("<SCRIPT> alert ('Select Upload File! '); </SCRIPT> ");
Response. End ();
Return;
}
System. Web. httppostedfile file = request. Files [0];
String filename = request ["FILENAME"];
String save_path = "./attached /";
String ext = system. Io. Path. getextension (file. filename). tolower ();
Response. Write (EXT );
If (! System. Io. Directory. exists (server. mappath (save_path )))
System. Io. Directory. createdirectory (server. mappath (save_path ));
If (EXT = ". jpg" | ext = ". GIF" | ext = ". BMP" | ext = ". PNG "){
File. saveas (server. mappath (save_path + filename ));
Response. write ("<SCRIPT type = \" text/JavaScript \ "> parent. kindinsertimage ('"+ save_path + filename +"', '"+ request [" imgwidth "] +"', '"+ request [" imgheight "] + "', '"+ request [" imgborder "] +"'); </SCRIPT> '");
Response. End ();
}
Else {
Response. Write ("<SCRIPT> alert ('file format not supported! '); </SCRIPT> ");
Response. End ();
}
}

You only need to figure out the two objects httppostedfile and httpfilecollection, and it is not difficult to write batch file uploads.