Web User ControlSometimes it may happen that you need a functionality is not  provided by built in ASP.net controls at that time developers can create ASP.net user controls or ASP.net custom controls.

  • User controls. User controls are containers into which you can put markup and Web server controls. You can then treat the user control as a unit and define properties and methods for it.
  • Custom controls. A custom control is a class that you write that derives from Control or WebControl.

To load any user control programmatically you need  to perform these two steps.

  1. Controls must be loaded
  2. Add the loaded control to control collection of loaded page.

For this i have created a usercontrol named as newcontrol

newcontrol Code

<%@ Control Language="VB" AutoEventWireup="false" CodeFile="newcontrol.ascx.vb" Inherits="newcontrol" %>
<asp:Label ID="Label1" runat="server" 
    Text="How to Load User Control Programmatically, Demo"></asp:Label>

Now i am loading this user control to a new page at runtime

Partial Class usercontrol
    Inherits System.Web.UI.Page

    Protected Sub btnload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnload.Click
        Dim controltoload As Control
            controltoload = Me.LoadControl("~\newcontrol.ascx")

        Catch ex As Exception

        End Try

    End Sub
End Class

How to Load User Control Programmatically