Abstract base class for managing a control's events. It maintains an enabled flag for each event as well as a nested 'in progress' count.
The following sample code illustrates how the event manager can be used to temporarily enable/disable events.
Imports Infragistics.Win.UltraWinGrid
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
If Me.ultraGrid1.ActiveRow Is Nothing Then Return
Dim eventManager As GridEventManager
' Get the grid's event manager.
' The event manager is used to temporarily disable events
' to prevent them from being raised. This can be very
' convenient in a situation where one or more properties
' are being set in code and the events they would normally
' raise would cause unnecessary or counter-productive
' code to be executed.
'
' Note: All events are enabled by default.
eventManager = Me.ultraGrid1.EventManager
' Disable the Before/AfterSelectChange events
eventManager.SetEnabled(GridEventIds.BeforeSelectChange, False)
eventManager.SetEnabled(GridEventIds.AfterSelectChange, False)
' Toggle the selection state of the active row.
' Note: This would normally cause the Before/AfterSelectChange
' events to be raised. However, since the above code disabled
' the events they won't be.
Me.ultraGrid1.ActiveRow.Selected = Not Me.ultraGrid1.ActiveRow.Selected
' Re-enable the Before/AfterSelectChange events
eventManager.SetEnabled(GridEventIds.BeforeSelectChange, True)
eventManager.SetEnabled(GridEventIds.AfterSelectChange, True)
' The 'AllEventsEnabled' property lets you enable/disable
' all events will a single line of code. If any event is
' disabled the 'AllEventsEnabled' property returns false.
If eventManager.AllEventsEnabled = False Then
eventManager.AllEventsEnabled = True
End If
' The event manager also exposes an 'IsEnabled' method
' to see if an event is enabled or disbled.
If False = eventManager.IsEnabled(GridEventIds.BeforeSelectChange) Then
eventManager.SetEnabled(GridEventIds.BeforeSelectChange, True)
End If
' The grid event manager also exposes overloaded
' 'IsEnabled' and 'SetEnabled' methods that take an
' event group so that, for example all 'Before' or all
' 'After' events can be enabled/disabled. If any event
' in the group is disabled the 'IsEnabled' method returns
' false.
If False = eventManager.IsEnabled(EventGroups.BeforeEvents) Then
eventManager.SetEnabled(EventGroups.BeforeEvents, True)
End If
eventManager.SetEnabled(EventGroups.AfterEvents, True)
' The 'InProgress' method will return true if the
' specified event is currently being raised. This
' is often helpful in methods that can be called
' from various points in an application to determine
' what is triggering the call.
If eventManager.InProgress(GridEventIds.BeforeSelectChange) Then
' ...
End If
' The UltraCombo and UltraDropDown controls also expose
' event managers for their custom events. However,
' since they have considerably fewer events they don't
' expose overloaded 'IsEnabled' and 'SetEnabled' methods
' to control groups of events.
Dim comboManager As ComboEventManager
comboManager = Me.ultraCombo1.EventManager
comboManager.SetEnabled(ComboEventIds.BeforeDropDown, True)
Dim dropDownManager As DropDownEventManager
dropDownManager = Me.UltraDropDown1.EventManager
dropDownManager.SetEnabled(DropDownEventIds.AfterCloseUp, True)
End Sub
'Declaration
Public MustInherit Class EventManagerBase
using Infragistics.Win.UltraWinGrid;
private void button2_Click(object sender, System.EventArgs e)
{
if ( this.ultraGrid1.ActiveRow == null )
return;
// Get the grid's event manager.
// The event manager is used to temporarily disable events
// to prevent them from being raised. This can be very
// convenient in a situation where one or more properties
// are being set in code and the events they would normally
// raise would cause unnecessary or counter-productive
// code to be executed.
//
// Note: All events are enabled by default.
GridEventManager eventManager = this.ultraGrid1.EventManager;
// Disable the Before/AfterSelectChange events
eventManager.SetEnabled( GridEventIds.BeforeSelectChange, false );
eventManager.SetEnabled( GridEventIds.AfterSelectChange, false );
// Toggle the selection state of the active row.
// Note: This would normally cause the Before/AfterSelectChange
// events to be raised. However, since the above code disabled
// the events they won't be.
this.ultraGrid1.ActiveRow.Selected =
!this.ultraGrid1.ActiveRow.Selected;
// Re-enable the Before/AfterSelectChange events
eventManager.SetEnabled( GridEventIds.BeforeSelectChange, true );
eventManager.SetEnabled( GridEventIds.AfterSelectChange, true );
// The 'AllEventsEnabled' property lets you enable/disable
// all events will a single line of code. If any event is
// disabled the 'AllEventsEnabled' property returns false.
if ( !eventManager.AllEventsEnabled )
eventManager.AllEventsEnabled = true;
// The event manager also exposes an 'IsEnabled' method
// to see if an event is enabled or disbled.
if ( !eventManager.IsEnabled(GridEventIds.BeforeSelectChange ) )
eventManager.SetEnabled(GridEventIds.BeforeSelectChange, true );
// The grid event manager also exposes overloaded
// 'IsEnabled' and 'SetEnabled' methods that take an
// event group so that, for example all 'Before' or all
// 'After' events can be enabled/disabled. If any event
// in the group is disabled the 'IsEnabled' method returns
// false.
if ( !eventManager.IsEnabled(EventGroups.BeforeEvents ) )
eventManager.SetEnabled(EventGroups.BeforeEvents, true );
eventManager.SetEnabled(EventGroups.AfterEvents, true );
// The 'InProgress' method will return true if the
// specified event is currently being raised. This
// is often helpful in methods that can be called
// from various points in an application to determine
// what is triggering the call.
if ( eventManager.InProgress( GridEventIds.BeforeSelectChange ) )
{
// ...
}
// The UltraCombo and UltraDropDown controls also expose
// event managers for their custom events. However,
// since they have considerably fewer events they don't
// expose overloaded 'IsEnabled' and 'SetEnabled' methods
// to control groups of events.
ComboEventManager comboManager = this.ultraCombo1.EventManager;
comboManager.SetEnabled( ComboEventIds.BeforeDropDown, true );
DropDownEventManager dropDownManager = this.ultraDropDown1.EventManager;
dropDownManager.SetEnabled( DropDownEventIds.AfterCloseUp, true );
}
'Declaration
Public MustInherit Class EventManagerBase
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
