Using a ControlBuilder : WebControl « Custom Controls « ASP.NET Tutorial






File: ServerTabs.cs

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

namespace myControls
{
    [ControlBuilder(typeof(ServerTabsBuilder))]
    [ParseChildren(false)]
    public class ServerTabs : WebControl, IPostBackEventHandler
    {
        public int SelectedTabIndex
        {
            get
            {
                if (ViewState["SelectedTabIndex"] == null)
                    return 0;
                else
                    return (int)ViewState["SelectedTabIndex"];
            }            set
            {
                ViewState["SelectedTabIndex"] = value;
            }
        }

        protected override void RenderContents(HtmlTextWriter writer)
        {
            for (int i = 0; i < this.Controls.Count; i++)
            {
                ServerTab tab = (ServerTab)this.Controls[i];
                string eRef = Page.ClientScript.GetPostBackClientHyperlink(this,  i.ToString());

                if (SelectedTabIndex == i)
                    writer.AddAttribute(HtmlTextWriterAttribute.Class, "tab  selectedTab");
                else
                    writer.AddAttribute(HtmlTextWriterAttribute.Class, "tab");
                writer.RenderBeginTag(HtmlTextWriterTag.Div);
                writer.AddAttribute(HtmlTextWriterAttribute.Href, eRef);
                writer.RenderBeginTag(HtmlTextWriterTag.A);
                writer.Write(tab.Text);
                writer.RenderEndTag();
                writer.RenderEndTag();
            }
            writer.Write("<br style='clear:both' />");

            writer.AddAttribute(HtmlTextWriterAttribute.Class, "tabContents");
            writer.RenderBeginTag(HtmlTextWriterTag.Div);
            this.Controls[SelectedTabIndex].RenderControl(writer);
            writer.RenderEndTag(); 
        }

        protected override void AddParsedSubObject(object obj)
        {
            if (obj is ServerTab)
                base.AddParsedSubObject(obj);
        }

        protected override HtmlTextWriterTag TagKey
        {
            get
            {
                return HtmlTextWriterTag.Div;

            }
        }

        public void RaisePostBackEvent(string eventArgument)
        {
            SelectedTabIndex = Int32.Parse(eventArgument);
        }
    }

    public class ServerTabsBuilder : ControlBuilder
    {
        public override Type GetChildControlType(string tagName, IDictionary attribs)
        {
            if (String.Compare(tagName, "tab", true) == 0)
                return typeof(ServerTab);
            else
                return null;
        }
    }

    public class ServerTab : Control
    {
        private string _Text;

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

            
File: ShowServerTabs.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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <style type="text/css">
        .tab
        {
            float:left;
            position:relative;
            top:1px;
            background-color:#eeeeee;
            border:solid 1px black;
            padding:0px 15px;
            margin-left:5px;
        }
        .tab a
        {
            text-decoration:none;
        }
        .selectedTab
        {
            background-color:white;
            border-bottom:solid 1px white;
        }
        .tabContents
        {
            border:solid 1px black;
            background-color:white;
            padding:10px;
            height:200px;
        }
    </style>
    <title>Show ServerTabs</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <custom:ServerTabs
        ID="ServerTabs1"
        Runat="Server">
        <tab Text="First Tab">
          Contents of the first tab
        </tab>
        <tab Text="Second Tab">
          Contents of the second tab
        </tab>
        <tab Text="Third Tab">
          Contents of the third tab
        </tab>
    </custom:ServerTabs>

    </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