Hello drpoalim,

Please feel free to contact me if any additional questions regarding this scenario arise.

Great!

Thanks.

Hello drpoalim,

It should be possible to use the control's Init event for this task.

Please let me know if this helps.

Thanks.

Is it possible to do it on any of the control's events?

I want to create my own inherited control from your control.

Hello drpoalim,

Thank you for your reply.

Setting the ImageUrl dynamically from the code behind should be done at the PreInit stage (Init stage if a master page is used) in order to ensure that the control's viewstate is properly reloaded:

    protected override void OnPreInit(EventArgs e)     {         
            base.OnPreInit(e);         
            WebDatePicker2.Buttons.CustomButton.ImageUrl = "ig_res/Default/images/igmc_headerbg.png";     
    }

Hope this helps.