Gets or sets a comma-separated list of MIME encodings used to constrain the file types the user can select.
Assembly: System.Web (in System.Web.dll)
Use this property to specify the file type that can be uploaded to the server. For example, to restrict the selection to images, set this property to "image/*".
.gif) Note |
|---|
Support for this property is browser-dependent. Check your browser to determine whether it supports this property. It is recommended that you use server-side code to ensure that the file is of the expected type. |
The following code example demonstrates how to use the Accept property to restrict the user from selecting any file other than an image file. For this example to work properly, you need to create a directory called Temp on your computer's drive C. Because support for the Accept property is browser-dependent, a server-side check is performed to ensure that only images are uploaded. An exception is thrown if the uploaded file can not be read as an Image type.
<%@ Page Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
' Check to see if a file was selected.
If (Text1.Value = "") Then
Span1.InnerHtml = "Error: You must enter a file name."
Return
End If
' Save the file
If (File1.PostedFile.ContentLength > 0) Then
Try
Try
Using input As System.Drawing.Image = _
System.Drawing.Image.FromStream(File1.PostedFile.InputStream)
File1.PostedFile.SaveAs("c:\\temp\\" & _
Server.HtmlEncode(Text1.Value))
Span1.InnerHtml = "File uploaded successfully to <b>c:\\temp\\" & _
Server.HtmlEncode(Text1.Value) & _
"</b> on the Web server."
End Using
Catch
Throw New Exception("Not a valid image file.")
End Try
Catch exc As Exception
Span1.InnerHtml = "Error saving file <b>c:\\temp\\" & _
Server.HtmlEncode(Text1.Value) & _
"</b>. " & exc.Message
End Try
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>HtmlInputFile Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
Select File to Upload:
<input id="File1"
type="file"
accept="image/jpeg"
runat="server"/>
<p>
Save as file name (no path):
<input id="Text1"
type="text"
runat="server"/>
</p>
<p>
<span id="Span1"
style="font: 8pt verdana;"
runat="server" />
</p>
<p>
<input type="button"
id="Button1"
value="Upload"
onserverclick="Button1_Click"
runat="server" />
</p>
</div>
</form>
</body>
</html>
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Button1_Click(object Source, EventArgs e)
{
// Check to see if a file was selected.
if (Text1.Value == "")
{
Span1.InnerHtml = "Error: You must enter a file name.";
return;
}
// Save the file.
if (File1.PostedFile.ContentLength > 0)
{
try
{
try
{
using (System.Drawing.Image input =
System.Drawing.Image.FromStream(File1.PostedFile.InputStream))
{
File1.PostedFile.SaveAs("c:\\temp\\" +
Server.HtmlEncode(Text1.Value));
Span1.InnerHtml = "File uploaded successfully to <b>c:\\temp\\" +
Server.HtmlEncode(Text1.Value) +
"</b> on the Web server.";
}
}
catch
{
throw new Exception("Not a valid image file.");
}
}
catch (Exception exc)
{
Span1.InnerHtml = "Error saving file <b>c:\\temp\\" +
Server.HtmlEncode(Text1.Value) +
"</b>. " + exc.Message;
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>HmtlInputFile Example</title>
</head>
<body>
<form id="Form1" enctype="multipart/form-data"
runat="server">
<div>
Select File to Upload:
<input id="File1"
type="file"
accept="image/*"
runat="server"/>
<p>
Save as file name (no path):
<input id="Text1"
type="text"
runat="server"/>
</p>
<p>
<span id="Span1"
style="font: 8pt verdana;"
runat="server" />
</p>
<p>
<input type="button"
id="Button1"
value="Upload"
onserverclick="Button1_Click"
runat="server" />
</p>
</div>
</form>
</body>
</html>
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.