How to add a Custom Button on TopToolBar of HTML Editor

As to the new AjaxControlToolkit control HTML Editor, if some one wants to add a custom button onto TopToolBar of Editor and do some custom code, you can add a MethodButton and define client-side onclick to do script. It's no way to define server-side onclick of it. However, you can build a doPostBack functionality on client if you'd like to do onclick on the server-side.

public class CustomEditor : AjaxControlToolkit.HTMLEditor.Editor
{
public CustomEditor()
{
//
// TODO: Add constructor logic here
//
}


protected override void FillTopToolbar()
{
//base.FillTopToolbar();

AjaxControlToolkit.HTMLEditor.ToolbarButton.MethodButton btn=new AjaxControlToolkit.HTMLEditor.ToolbarButton.MethodButton();
btn.NormalSrc= "aa.jpg";
btn.Attributes.Add("onclick", "alert('a');");
TopToolbar.Buttons.Add(btn);

}

}

Update:

This new feature has been added to Editor control. You can download it and create custom button in editor control:

http://ajaxcontroltoolkit.codeplex.com/SourceControl/changeset/view/54501