Use the ControlDesigner.CreateErrorDesignTimeHtml(string) method to create HTML markup to display an error message for a control at design time. The value for errorMessage specifies a localized string that is displayed to the user of the control at design time.

The System.Web.UI.Design.ControlDesigner class implementation of the ControlDesigner.CreateErrorDesignTimeHtml(string) method returns a table with two rows, as follows:

• The first row contains the type name and site name for the System.ComponentModel.Design.ComponentDesigner.Component property of the System.Web.UI.Design.ControlDesigner object.

• The second row contains the input error message string.

To generate HTML markup for an error message with an associated exception, use the ControlDesigner.CreateErrorDesignTimeHtml(string, Exception) overload. To generate HTML markup for an exception without specifying a localized error message, use the ControlDesigner.GetErrorDesignTimeHtml(Exception) method.