View State and Control State : WebControl « Custom Controls « ASP.NET Tutorial






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

namespace myControls
{
    public class ViewStateControl : WebControl
    {
        private string _text;

        public string Text
        {
            get { return _text; }
            set { _text = value; }
        }
        public string ViewStateText
        {
            get
            {
                if (ViewState["ViewStateText"] == null)
                    return String.Empty;
                else
                    return (string)ViewState["ViewStateText"];
            }
            set { ViewState["ViewStateText"] = value; }
        }

        protected override void RenderContents(HtmlTextWriter writer)
        {
            writer.Write("Text: " + Text);
            writer.WriteBreak();
            writer.Write("ViewStateText: " + ViewStateText);
            writer.WriteBreak();
        }

    }
}

            
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">

    void Page_Load()
    {
        if (!Page.IsPostBack)
        {
            ViewStateControl1.Text = "Hello World!";
            ViewStateControl1.ViewStateText = "Hello World!";
        }
    }

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Show View State</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

    <custom:ViewStateControl
        id="ViewStateControl1"
        Runat="server" />

    <asp:Button
        id="btnSubmit"
        Text="Submit"
        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