Designer visibility of templated server control children

ScottyMac — Fri, 02 Nov 2007 04:00:00 GMT

Hello World,

I have templated custom server control, which works ok, but the visual studio designer
cannot properly "see" the child controls within the template, for code-behind work and the such.

<cc1:mycontrol runat="server">
<template>
<asp:label runat="server" id="mylabel">
</template>
</cc1:mycontrol>

If i set the PersistChilden/ParseChildren one way (false/true), visual studio does not "see" the MyLabel
control and gives an undefined variable compile error. If I set them the other way (true/false), then i
can no longer use FindControl to find Mylabel by searching the page control hierarchy.

Any hints on how to get both methods to work?

Re: Latest release has problem with custom controls w/ParseChildren(false)...?

rodrigoelp — Tue, 03 Jul 2007 04:00:00 GMT

Erm, I would like to know if you guys could resolve this problem.

Currently I am having the same issue, my control is a little different than the proposed in the topic, but I am having the same error message and I have tried almost everything (obviously not the right things.)

My problem is described next:

I am having a custom UserControl with a generic list containing class instances of a class I made. The UserControl also has the ParseChildren attribute with the parsing flag on true and the default property named to my List of elements.

When I write the control tag name everything is ok, the intellisense shows everything and compiles ok. In fact my only problem is when I switch back to design mode getting the “Type ‘System.Web.UI.UserControl’ does not have a property named ‘ObjectListItem’” which is the class’ name of the item stored within the generic list.

This is a big issue for me because the designers are complaining about the page layout when trying to edit anything or just move the controls. And i would like to know if theres a workaround or what i am doing wrong to correct it as fast as possible. Thanks.

Here is the source code sample where you can reproduce the error:

This is the element code which will contain the information.

1    //Item to store within the UserControl.
2    namespace CustomControls
3    {
4        public class MyItem
5        {
6            private string m_Name;
7            public string Name
8            {
9                get { return m_Name; }
10               set { m_Name = value; }
11           }
12       }
13   }

This is the Custom web UserControl code behind.

 1    using System;
2    using System.Data;
3    using System.Configuration;
4    using System.Collections;
5    using System.Web;
6    using System.Web.Security;
7    using System.Web.UI;
8    using System.Web.UI.WebControls;
9    using System.Web.UI.WebControls.WebParts;
10   using System.Web.UI.HtmlControls;
11   
12   using System.Collections.Generic;
13   using CustomControls;
14   
15   [ParseChildren(true, "ItemList")]
16   [PersistChildren(false)]
17   [PersistenceMode(PersistenceMode.InnerProperty)]
18   public partial class controls_MyWebUserControl : System.Web.UI.UserControl
19   {
20       private List m_Items = new List();
21       public List ItemList //this is the element not found by the designer.
22       {
23           get { return m_Items; }
24       }
25       protected void Page_Load(object sender, EventArgs e) { }
26   
27       protected override void CreateChildControls()
28       {
29           if (this.DropDownList1.Items.Count != ItemList.Count)
30           {
31               for (int i = 0; i < ItemList.Count; i++)
32               {
33                   this.DropDownList1.Items.Add(new ListItem(ItemList[i].Name, ItemList[i].Name));
34               }
35           }
36           base.CreateChildControls();
37       }
38       protected void Button1_Click(object sender, EventArgs e){ }
39   }
 
This is the UserControl ascx.

1    <%@ Control Language="C#" AutoEventWireup="true" CodeFile="MyWebUserControl.ascx.cs" Inherits="controls_MyWebUserControl" %>
2    <-asp:Label "Label1" runat="server" Text="">
3    <-asp:TextBox "TextBox1" runat="server">
4    <-asp:DropDownList "DropDownList1" runat="server"><%-- I had to add a line between the asp flag to avoid the tool from removing it. --%>
5    
6    <-asp:Button "Button1" runat="server" OnClick="Button1_Click" Text="Button" />
Code in the aspx page where i want the control with some parameters. There is no need to add extra code behind to the page except the one auto generated by vs.
1    <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
2    <%@ Register TagPrefix="custom" Namespace="CustomControls" %>
3    <%@ Register src="~/controls/MyWebUserControl.ascx" TagName="MyWebUserControl" TagPrefix="custom" %>
4    "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
5    <-html xmlns="http://www.w3.org/1999/xhtml">
6    <-head runat="server">
7        <-title>Test Page
8    <-/head>
9    <-body>
10       <-form id="form1" runat="server">
11           <-asp:ScriptManager ID="ScriptManager1" runat="server" />
12           <-div>
13               <-custom:MyWebUserControl ID="xx1" runat="server">
14                   <-custom:MyItem Name="Item name 1" />
15                   <-custom:MyItem Name="Item name 2" />
16                   <-custom:MyItem Name="Item name 3" />
17                   <-custom:MyItem Name="Item name 4" />
18               <-/custom:MyWebUserControl>
19           <-/div>
20       <-/form>
21   <-/body>
22   <-/html>
 
Compile and switch to design mode in the default.aspx page (or anyone that you may have done containing the UserControl). 
Thanks in advance.

Search results matching tag 'parsechildren'

Designer visibility of templated server control children

Re: Latest release has problem with custom controls w/ParseChildren(false)...?