Validation groups allow you to assign validation controls on a page to a specific category. Each validation group can be validated independently of other validation groups on the page. Use the ImageButton.ValidationGroup property to specify the name of the validation group for which the System.Web.UI.WebControls.ImageButton control causes validation when it posts back to the server. This property has an effect only when the value of the ImageButton.CausesValidation property is set to true. When you specify a value for the ImageButton.ValidationGroup property, only the validation controls that are part of the specified group are validated when the System.Web.UI.WebControls.ImageButton control posts back to the server. If you do not specify a value for this property and the ImageButton.CausesValidation property is set to true, all validation controls on the page that are not assigned to a validation group are validated when the control posts back to the server.

This property cannot be set by themes or style sheet themes. For more information, see System.Web.UI.ThemeableAttribute and ASP.NET Themes Overview.