Infragistics logo
메뉴
.NET and JavaScript UI Controls
Version

EventManagerBase Class

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.
Syntax
'Declaration
 
Public MustInherit Class EventManagerBase 
public abstract class EventManagerBase
Example
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
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 );

}
Requirements

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

See Also