How to Use the FileUpload File Upload Control

// Creation Time:

// Created by: Yulin Lone Wolf

// Description: Instructions for using the FileUpload File Upload control (only part of it)

//You can upload images and txt files. Doc, wps, and audio files and video files. Powerful functions!

// Front-end code piece, set the Image Upload Interface

<Div>

<Asp: Label ID = "lbText" runat = "server" Font-Bold = "true" Font-Size = "20px" Text = "select the photo you want to upload">

</Asp: Label>

<Br/> <asp: Label ID = "lbImg" runat = "server" ForeColor = "Red"> </asp: Label> <br/>

<Asp: Label ID = "hh" runat = "server" Text = "Upload path:"> </asp: Label> <br/>

<Asp: TextBox ID = "txtFileName" runat = "server"> </asp: TextBox>

<Asp: FileUpload ID = "FileUpLoad1" runat = "server"/>

<Asp: Button ID = "btnUpload" runat = "server" Text = "Start upload" OnClick = "btnUpload_Click"/> <br/>

<Asp: Label ID = "hj" runat = "server" Text = "The uploaded image is as follows"> </asp: Label>

<Br/> <asp: Image ID = "img" runat = "server"/>

</Div>

// Background code for uploading images from the client to the server

Protected void btnUpload_Click (object sender, EventArgs e)

{// HasFile gets a value indicating whether the FileUpload control contains a file.

If ()

{

// PostedFile obtains the basic HttpPostedFile object by using the File Uploaded By the FileUpload control. Public HttpPostedFile

// PostedFile {get ;}

String fileContentType = FileUpLoad1.PostedFile. ContentType;

// You can also use file. Extension to determine the file type, as shown in figure

If (fileContentType = "image/jpeg" | fileContentType = "image/bmp" | fileContentType = "image/gif" |

FileContentType = "image/png ")

{

// Client file path

String name = FileUpLoad1.PostedFile. FileName;

// File name

String filename = file. Name;

// Server File Path

This.txt FileName. Text = filename;

String webFilePath = Server. MapPath ("Upload/" + filename );

// Determine whether the same file exists

If (! File. Exists (webFilePath ))

{

Try {

// Use SqveAs () to save the content of the uploaded file to the specified path on the Web Server

This. lbImg. Text = "prompt: the file" "+ filename +" is uploaded successfully! ";

This. img. ImageUrl = "Upload/" + filename;

}

Catch (Exception ex ){

This. lbImg. Text = "File Upload Failed because" + ex. Message;

}

}

}

Else

{This. lbImg. Text = "the file type does not match ";

}

}

}