Asp. NET Knowledge Summary (5. File upload 6. File download)

5. File Upload

-"NOTE: Using the HTTP protocol is only suitable for transferring small files, if you want to pass large files, you need to use plug-in or client program (using FTP protocol)

-"Client action"

"1"adds attributes to the form:enctype= "Multipart/form-data"

"2"adding Controls to the form:<input type= "file" name= "F1"/>

"3" form must use post submission method

-"server-side operations"

"1" using the request.files property to get the file object

2Savewith the SaveAs () method of the httppostedfile Object

-"Observe the data message

When you set the enctype= "Multipart/form-data" property of a form, it is no longer the key-value format, but instead uses the delimiter in the request body

-"limit: Upload executable file is not allowed, only allow static file upload

Example: Only upload images are allowed

Client-side Checksum

Server-side Check

-"Improve: Save the file to the corresponding year, month, and Day folder for easy traversal

Dynamically creating paths

Stitching path Information

Example:ASPNET Project Review / /t1_upload_downloadof the next day

6. File Download

-"Use hyperlinks to directly specify the files to download

Text that can be parsed by the browser will be displayed

Files that cannot be parsed by the browser will be downloaded

-"Implementation: No matter the file format, do not use the browser display, complete the download

Point to generic handler, file address as parameter

Modify the response header:ContentType = "Application/octet-stream";

Set header information:addheader ("content-disposition", "attachment; Filename=\ " file name \"; ");

Output file:context. Response.WriteFile ( file address );

-"Hint: If the Chinese file name is garbled, URL encoding can be

Httputility.urlencode (filename, System.Text.Encoding.UTF8);

Returns a string as the name of the file

Example:ASPNET Project Review / /t1_upload_downloadof the next day

Asp. NET Knowledge Summary (5. File upload 6. File download)