How to get unique ClientId in Custom .NET Server Control
If you use RenderContents to render child controls in your Render method of a custom web control, the ID will not be set to unique like it is when you add the controls as children of your web control.
To fix, update the ID programmatically prior to rendering the child control.
public class CustomBox : TextBox
Label lblResult = new Label();
protected override void Render(System.Web.UI.HtmlTextWriter writer)
base.Render(writer); // render me
writer.WriteBreak(); // render some HTML
lblResult.ID = Parent.ClientID + "_lblResult"; // generate valid unique id
lblResult.RenderControl(writer); // render a child
Created By: amos 4/16/2015 2:42:40 PM
Updated: 4/16/2015 2:43:50 PM