Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.Windows.Design.Interaction
Imports System.Windows
Imports Microsoft.Windows.Design.Model
Imports System.Windows.Controls
Imports System.Windows.Media
' The CustomContextMenuProvider class provides two context menu items
' at design time. These are implemented with the MenuAction class.
Class CustomContextMenuProvider
Inherits PrimarySelectionContextMenuProvider
Private setBackgroundToBlueMenuAction As MenuAction
Private clearBackgroundMenuAction As MenuAction
' The provider's constructor sets up the MenuAction objects
' and the the MenuGroup which holds them.
Public Sub New()
' Set up the MenuAction which sets the control's
' background to Blue.
setBackgroundToBlueMenuAction = New MenuAction("Blue")
setBackgroundToBlueMenuAction.Checkable = True
AddHandler setBackgroundToBlueMenuAction.Execute, AddressOf SetBackgroundToBlue_Execute
' Set up the MenuAction which sets the control's
' background to its default value.
clearBackgroundMenuAction = New MenuAction("Cleared")
clearBackgroundMenuAction.Checkable = True
AddHandler clearBackgroundMenuAction.Execute, AddressOf ClearBackground_Execute
' Set up the MenuGroup which holds the MenuAction items.
Dim backgroundFlyoutGroup As New MenuGroup("SetBackgroundsGroup", "Set Background")
' If HasDropDown is false, the group appears inline,
' instead of as a flyout. Set to true.
backgroundFlyoutGroup.HasDropDown = True
backgroundFlyoutGroup.Items.Add(setBackgroundToBlueMenuAction)
backgroundFlyoutGroup.Items.Add(clearBackgroundMenuAction)
Me.Items.Add(backgroundFlyoutGroup)
' The UpdateItemStatus event is raised immediately before
' this provider shows its tabs, which provides the opportunity
' to set states.
AddHandler UpdateItemStatus, AddressOf CustomContextMenuProvider_UpdateItemStatus
End Sub
' The following method handles the UpdateItemStatus event.
' It sets the MenuAction states according to the state
' of the control's Background property. This method is
' called before the context menu is shown.
Sub CustomContextMenuProvider_UpdateItemStatus( _
ByVal sender As Object, _
ByVal e As MenuActionEventArgs)
' Turn everything on, and then based on the value
' of the BackgroundProperty, selectively turn some off.
clearBackgroundMenuAction.Checked = False
clearBackgroundMenuAction.Enabled = True
setBackgroundToBlueMenuAction.Checked = False
setBackgroundToBlueMenuAction.Enabled = True
' Get a ModelItem which represents the selected control.
Dim selectedControl As ModelItem = _
e.Selection.PrimarySelection
' Get the value of the Background property from the ModelItem.
Dim backgroundProperty As ModelProperty = _
selectedControl.Properties(Control.BackgroundProperty)
' Set the MenuAction items appropriately.
If Not backgroundProperty.IsSet Then
clearBackgroundMenuAction.Checked = True
clearBackgroundMenuAction.Enabled = False
ElseIf backgroundProperty.ComputedValue.Equals(Brushes.Blue) Then
setBackgroundToBlueMenuAction.Checked = True
setBackgroundToBlueMenuAction.Enabled = False
End If
End Sub
' The following method handles the Execute event.
' It sets the Background property to its default value.
Sub ClearBackground_Execute( _
ByVal sender As Object, _
ByVal e As MenuActionEventArgs)
Dim selectedControl As ModelItem = e.Selection.PrimarySelection
selectedControl.Properties(Control.BackgroundProperty).ClearValue()
End Sub
' The following method handles the Execute event.
' It sets the Background property to Brushes.Blue.
Sub SetBackgroundToBlue_Execute( _
ByVal sender As Object, _
ByVal e As MenuActionEventArgs)
Dim selectedControl As ModelItem = e.Selection.PrimarySelection
selectedControl.Properties(Control.BackgroundProperty).SetValue(Brushes.Blue)
End Sub
End Class