James Gomount wrote:
> I want to build a control that can dynamically display different sub
> controls.
> For example, there is a dropdownlist and a submit button. When an
> item is selected from the drop down list and the user press the
> button, I want to display other controls (i.e. Textbox and buttons)
> depending on the item selected in the dropdownlist.
>
> I think I should create a web custom control, but I am not sure where
> I should create and display the sub controls (maybe in
> CreateChildControls).
>
> Is there any samples or good references for things like that?

"James Gomount" <jgomount@yahoo.com> wrote in message
news:ORWdxJYzDHA.2000@TK2MSFTNGP11.phx.gbl...
> I made a small sample with a Web user control. With the web user control
> everything works fine, but when I try to convert this to a Web custom
> control I have problems with the Postback.
>
> Any hints on how to make this a custom control?
>
> Code is below.
>
> WebUserControl1.ascx
> ------------------------
> namespace DynUpdateTest
> {
> using System;
> using System.Data;
> using System.Drawing;
> using System.Web;
> using System.Web.UI;
> using System.Web.UI.WebControls;
> using System.Web.UI.HtmlControls;
>
> /// <summary>
> /// Summary description for WebUserControl1.
> /// </summary>
> public class WebUserControl1 : System.Web.UI.UserControl
> {
> protected System.Web.UI.WebControls.DropDownList ddl;
> protected System.Web.UI.WebControls.Panel panelField;
> protected System.Web.UI.WebControls.Label lblResult;
>
> public int MaxItems
> {
> get { return _maxItems; }
> set { _maxItems = value; }
> }
> private int _maxItems;
>
> private void Page_Load(object sender, System.EventArgs e)
> {
> if (!IsPostBack)
> {
> ddl.Items.Add("-- Select an item --");
> for (int i=1; i<=_maxItems; i++)
> ddl.Items.Add(i.ToString());
> }
>
> if (ddl.SelectedIndex > 0)
> {
> for (int i=0; i<ddl.SelectedIndex; i++)
> {
> TextBox box = new TextBox();
> box.ID = "box_" + ddl.SelectedItem + "_" + i.ToString();
> panelField.Controls.Add(new LiteralControl("<b>" + box.ID + ":
</b>"));
> panelField.Controls.Add(box);
> panelField.Controls.Add(new LiteralControl("<br>"));
> }
>
> Button cmdSubmit = new Button();
> cmdSubmit.ID = "cmdSubmit";
> cmdSubmit.Text = "Send";
> cmdSubmit.Click += new EventHandler(cmdSubmit_Click);
> panelField.Controls.Add(cmdSubmit);
>
> }
> }
>
> #region Web Form Designer generated code
> override protected void OnInit(EventArgs e)
> {
> //
> // CODEGEN: This call is required by the ASP.NET Web Form Designer.
> //
> InitializeComponent();
> base.OnInit(e);
> }
>
> /// <summary>
> /// Required method for Designer support - do not modify
> /// the contents of this method with the code editor.
> /// </summary>
> private void InitializeComponent()
> {
> this.ddl.SelectedIndexChanged += new
> System.EventHandler(this.ddl_SelectedIndexChanged);
> this.Load += new System.EventHandler(this.Page_Load);
>
> }
> #endregion
>
> private void cmdSubmit_Click(object sender, EventArgs e)
> {
> //Show the results
> lblResult.Text = "";
>
> foreach (Control ctr in panelField.Controls)
> {
> if (ctr is TextBox)
> {
> TextBox txt = (TextBox) ctr;
> lblResult.Text += String.Format("{0} -> {1}<br>", txt.ID, txt.Text);
> }
> }
> }
>
> private void ddl_SelectedIndexChanged(object sender, System.EventArgs e)
> {
> lblResult.Text = "";
> }
> }
> }
>
>
> -----------
> WebUserControl1.ascx
> ----------
> <%@ Control Language="c#" AutoEventWireup="false"
> Codebehind="WebUserControl1.ascx.cs"
> Inherits="DynUpdateTest.WebUserControl1"
> TargetSchema="http://schemas.microsoft.com/intellisense/ie5"%>
> <asp:DropDownList id="ddl" runat="server" AutoPostBack="True"
> Width="167px"></asp:DropDownList>
> <HR width="100%" SIZE="1">
> <asp:Panel id="panelField" runat="server"></asp:Panel>
> <HR width="100%" SIZE="1">
> <asp:Label id="lblResult" runat="server"></asp:Label>
>
>
> -----
> WebForm4.aspx.cs
> ------
> <%@ Page language="c#" Codebehind="WebForm4.aspx.cs"
AutoEventWireup="false"
> Inherits="DynUpdateTest.WebForm4" %>
> <%@ Register TagPrefix="uc1" TagName="WebUserControl1"
> Src="WebUserControl1.ascx" %>
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
> <HTML>
> <HEAD>
> <title>WebForm4</title>
> <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
> <meta name="CODE_LANGUAGE" Content="C#">
> <meta name="vs_defaultClientScript" content="JavaScript">
> <meta name="vs_targetSchema"
> content="http://schemas.microsoft.com/intellisense/ie5">
> </HEAD>
> <body MS_POSITIONING="GridLayout">
> <form id="Form1" method="post" runat="server">
> <uc1:WebUserControl1 id="WebUserControl11" runat="server"
> MaxItems="5"></uc1:WebUserControl1>
> </form>
> </body>
> </HTML>
>
>

> I want to build a control that can dynamically display different sub
> controls.
> For example, there is a dropdownlist and a submit button. When an item is
> selected from the drop down list and the user press the button, I want to
> display other controls (i.e. Textbox and buttons) depending on the item
> selected in the dropdownlist.
>
> I think I should create a web custom control, but I am not sure where I
> should create and display the sub controls (maybe in CreateChildControls).
>
> Is there any samples or good references for things like that?
>
>
>
>
> ---
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