Handling Postback Events : WebControl « Custom Controls « ASP.NET Tutorial






File: CustomLinkButton.cs

using System;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace myControls
{
    public class CustomLinkButton : WebControl, IPostBackEventHandler
    {
        public event EventHandler Click;

        private string _Text;

        public string Text
        {
            get { return _Text; }
            set { _Text = value; }
        }

        protected override void AddAttributesToRender(HtmlTextWriter writer)
        {
            string eRef = Page.ClientScript.GetPostBackClientHyperlink(this, String.Empty);
            writer.AddAttribute(HtmlTextWriterAttribute.Href, eRef);
            base.AddAttributesToRender(writer);
        }

        protected override HtmlTextWriterTag TagKey
        {
            get
            {
                return HtmlTextWriterTag.A;
            }
        }

        protected override void RenderContents(HtmlTextWriter writer)
        {
            writer.Write(_Text);
        }


        public void RaisePostBackEvent(string eventArgument)
        {
            if (Click != null)
                Click(this, EventArgs.Empty);
        }
    }
}

            
File: Default.aspx

<%@ Page Language="C#" %>
<%@ Register TagPrefix="custom" Namespace="myControls" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

    protected void CustomLinkButton1_Click(object sender, EventArgs e)
    {
        lblResults.Text = txtUserName.Text;
    }
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Show CustomLinkButton</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

    <asp:Label
        id="lblUserName"
        Text="User Name:"
        AssociatedControlID="txtUserName"
        Runat="server" />
    <asp:TextBox
        id="txtUserName"
        Runat="server" />

    <br /><br />

    <custom:CustomLinkButton
        id="CustomLinkButton1"
        Text="Submit"
        OnClick="CustomLinkButton1_Click"
        runat="server" />

    <hr />

    <asp:Label
        id="lblResults"
        EnableViewState="false"
        Runat="server" />

    </div>
    </form>
</body>
</html>








14.19.WebControl
14.19.1.A control that inherits from the WebControl class.
14.19.2.Displaying a table of HTML colors.
14.19.3.File: DropShadow.cs
14.19.4.Specifying the Containing WebControl Tag
14.19.5.View State and Control State
14.19.6.Supporting Control State
14.19.7.Processing Postback Data and Events
14.19.8.Handling Postback Events
14.19.9.contains the custom pager control.
14.19.10.Using Postback Options
14.19.11.Working with Control Property Collections
14.19.12.Using a ControlBuilder
14.19.13.Applying Design-Time Attributes to a Control
14.19.14.Creating a Container ControlDesigner
14.19.15.You can add your own Smart Tasks to a custom control by inheriting a new class from the base DesignerActionList class.
14.19.16.Your own data binding control