HtmlInputFile.OnPreRender Method (EventArgs)
.NET Framework (current version)
Raises the PreRender event for the HtmlInputFile control.
Assembly: System.Web (in System.Web.dll)
The following code example demonstrates how to override the OnPreRender method so that a Title attribute is always added to each custom HtmlInputFile control. For this example to work properly, you need to create a directory called Temp on your computer's drive C.
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %> <%@ Page Language="C#" AutoEventWireup="True" %> <!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) { // Make sure a file was submitted. if (HtmlInputText1.Value == "") { Span1.InnerHtml = "Error: You must enter a file name."; } // Save the file. else if (HtmlInputFile1.PostedFile != null) { try { HtmlInputFile1.PostedFile.SaveAs("c:\\temp\\" + HtmlInputText1.Value); Span1.InnerHtml = "File uploaded successfully to: <b>c:\\temp\\" + HtmlInputText1.Value + "</b> on the Web server."; } catch (Exception exc) { Span1.InnerHtml = "Error saving <b>c:\\temp\\" + HtmlInputText1.Value + "</b><br />" + exc.ToString() + "."; } } } </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head> <title>Custom HtmlInputFile OnPreRender Example</title> </head> <body> <form id="form1" enctype="multipart/form-data" runat="server"> <h3>Custom HtmlInputFile OnPreRender Example</h3> Select File to Upload: <aspSample:CustomHtmlInputFileOnPreRender id="HtmlInputFile1" type="file" runat="server" name="HtmlInputFile1"> <p> Save as file name (no path): <input id="HtmlInputText1" type="text" runat="server" name="Text1" /> </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" name="Button1" /> </p> </form> </body> </html>
using System.Web; using System.Security.Permissions; namespace Samples.AspNet.CS.Controls { [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)] public sealed class CustomHtmlInputFileOnPreRender : System.Web.UI.HtmlControls.HtmlInputFile { protected override void OnPreRender(System.EventArgs e) { // Call the base OnPreRender method. base.OnPreRender(e); // Add a Title attribute to the HtmlInputFile control. this.Attributes.Add("title", "Click the Browse button to select a file to upload."); } } }
.NET Framework
Available since 1.1
Available since 1.1
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