Sometimes, while creating controls, either by Inherited Controls or UserControls, we will be required to skip a piece of code depending upon the design time or runtime mode. This can be done easily by the following code inside a control.
If Me.Site IsNot Nothing AndAlso Me.Site.DesignMode = True Then 'Designtime code here Else 'Runtime code here End If
Using this code in a control, we can find the mode and avoid certain errors when in Design Mode. This is mostly used in overridden event methods in Inherited Controls.