Control designers use methods that are derived from the System.ComponentModel.Design.ComponentDesigner.PreFilterProperties(IDictionary) method to shadow various control properties with corresponding design-time properties that the designer implements, and to add or remove properties from the Properties grid.

For the System.Web.UI.WebControls.BaseDataBoundControl class, the BaseDataBoundControlDesigner.PreFilterProperties(IDictionary) shadows the BaseDataBoundControlDesigner.DataSource property of the control. It makes a copy of the attribute array of the BaseDataBoundControlDesigner.DataSource, and then adds these attributes to the shadowed property. It sets the System.ComponentModel.BrowsableAttribute.Browsable attribute of the shadowed BaseDataBoundControlDesigner.DataSource property to false unless the System.ComponentModel.BrowsableAttribute.Browsable attribute of the BaseDataBoundControlDesigner.DataSourceID property of the control is already set to true.