Example 1:
Use a regular expression to verify the type of the file to be uploaded. Remove <asp: RegularExpressionValidator/> to upload all
Default. aspx:
<% @ Page Language = "C #" AutoEventWireup = "true" CodeFile = "Default. aspx. cs" Inherits = "_ Default" %>
<! DOCTYPE html PUBLIC "-// W3C // dtd xhtml 1.0 Transitional // EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<HtmlXmlns = "http://www.w3.org/1999/xhtml">
<HeadRunat = "server">
<Title>No title page</Title>
</Head>
<Body>
<FormId = "form1" runat = "server">
<Asp: FileUploadID = "FileUpload1" runat = "server"/>
<Asp: ButtonID = "Button1" runat = "server" OnClick = "button#click" Text = "Button"/>
<Asp: RegularExpressionValidatorID = "RegularExpressionValidator1" runat = "server" ControlToValidate = "FileUpload1"
ErrorMessage = "must be a jpg or gif file" ValidationExpression = "^ ([a-zA-Z] :) | (\ {2} \ W +) \ $ ?) (\ W [\ W]. * ))((.jpg |. Jpg |. gif |. Gif) $"> </Asp: RegularExpressionValidator>
</Form>
</Body>
</Html>
Default. aspx. cs:
Using System;
Using System. Data;
Using System. Configuration;
Using System. Web;
Using System. Web. Security;
Using System. Web. UI;
Using System. Web. UI. WebControls;
Using System. Web. UI. WebControls. WebParts;
Using System. Web. UI. HtmlControls;
Public partial class _ Default: System. Web. UI. Page
{
Protected void Page_Load (object sender, EventArgs e)
{
}
Protected void button#click (object sender, EventArgs e)
{
String savePath = @ "F: \ Upload \";
If (FileUpload1.HasFile)
{
String filename;
Filename = FileUpload1.FileName;
SavePath + = filename;
FileUpload1.SaveAs (savePath );
Page. Response. Write (FileUpload1.PostedFile. ContentType + FileUpload1.PostedFile. ContentLength +"<Br>");
Page. Response. Write ("Src = '"+ savePath + "'>");
}
Else
{
Page. Response. Write ("fff ");
}
}
}
Example 2:
Obtain and verify the attributes of the uploaded file.
Protected void button#click (object sender, EventArgs e)
{
If (FileUpload1.HasFile)
{
FileExt = System. IO. Path. GetExtension (FileUpload1.FileName );
If (fileExt = ". rar" | fileExt = ". zip ")
{
Try
{
FileUpload1.SaveAs (Server. MapPath ("upload") + "\" + FileUpload1.FileName );
Label1.Text = "client path:" + FileUpload1.PostedFile. FileName + "<br>"+
"File name:" + System. IO. Path. GetFileName (FileUpload1.FileName) + "<br>"+
"File Extension:" + System. IO. Path. GetExtension (FileUpload1.FileName) + "<br>"+
"File size:" + FileUpload1.PostedFile. ContentLength + "KB <br>"+
"File MIME type:" + FileUpload1.PostedFile. ContentType + "<br>"+
"Save path:" + Server. MapPath ("upload") + "\" + FileUpload1.FileName;
}
Catch (Exception ex)
{
Label1.Text = "error:" + ex. Message. ToString ();
}
}
Else
{
Label1.Text = "only rar and zip files can be uploaded! ";
}
}
Else
{
Label1.Text = "no file to upload is selected! ";
}
}
Example 3:
Upload multiple files at a time, use the HttpFileCollection class to capture all files sent from the Request object, and then process each file separately.
Protected void button#click (object sender, EventArgs e)
{
String filepath = Server. MapPath ("upload") + "\\";
HttpFileCollection uploadFiles = Request. Files;
For (int I = 0; I <uploadFiles. Count; I ++)
{
HttpPostedFile postedFile = uploadFiles [I];
Try
{
If (postedFile. ContentLength>0)
{
Label1.Text + = "file #" + (I + 1) + ":" + System. IO. Path. GetFileName (postedFile. FileName) + "<br/>";
PostedFile. SaveAs (filepath + System. IO. Path. GetFileName (postedFile. FileName ));
}
}
Catch (Exception Ex)
{
Label1.Text + = "error:" + Ex. Message;
}
}
}
Example 4: Solve the size limit of uploaded files
In ASP. NET 2.0, the maximum size of the file to be uploaded by FileUpload is 4 MB by default. However, you can modify the default value in the web. cofig file.
Program code
<System. web>
<HttpRuntime maxRequestLength = "40690" executionTimeout = "6000"/>
</System. web>
MaxRequestLength indicates the maximum value of a file to be uploaded, and executionTimeout indicates the number of uploads allowed before ASP. NET is disabled.