'Declaration Public Property HeaderCheckBoxEventFiring As HeaderCheckBoxEventFiring
public HeaderCheckBoxEventFiring HeaderCheckBoxEventFiring {get; set;}
When a column header's CheckBoxVisibility property is set to a value which causes a checkbox to appear on the header, and that checkbox is clicked, the value of each cell in that column may be changed, subsequently causing the control's ValueChanged event to fire. This can affect performance in cases where the control has a relatively large number of rows. Setting this property to 'OnHeaderCheckboxValueChange' improves performance by deferring the firing of the ValueChanged event until after each cell's value has been changed.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2