VB.NET WorkflowDesignerMessageFilter類代碼示例

Friend NotInheritable Class CustomMessageFilter
        Inherits WorkflowDesignerMessageFilter

#Region "Members and Constructor"

        Private mouseDown As Boolean
        Private serviceProvider As IServiceProvider
        Private workflowView As WorkflowView
        Private loader As WorkflowDesignerLoader

        Public Sub New(ByVal provider As IServiceProvider, ByVal workflowView As WorkflowView, ByVal loader As WorkflowDesignerLoader)
            Me.serviceProvider = provider
            Me.workflowView = workflowView
            Me.loader = loader
        End Sub

#End Region

#Region "WorkflowDesignerMessageFilter Overridables"

        Protected Overrides Function OnMouseDown(ByVal eventArgs As System.Windows.Forms.MouseEventArgs) As Boolean
            ' Allow other components to process this event by not returning true.
            mouseDown = True
            Return False
        End Function

        Protected Overrides Function OnMouseMove(ByVal eventArgs As System.Windows.Forms.MouseEventArgs) As Boolean
            ' Allow other components to process this event by not returning true.
            If mouseDown Then
                workflowView.ScrollPosition = New Point(eventArgs.X, eventArgs.Y)
            End If
            Return False
        End Function

        Protected Overrides Function OnMouseUp(ByVal eventArgs As MouseEventArgs) As Boolean
            ' Allow other components to process this event by not returning true.
            mouseDown = False
            Return False
        End Function

        Protected Overrides Function OnMouseDoubleClick(ByVal eventArgs As MouseEventArgs) As Boolean
            mouseDown = False
            Return True
        End Function

        Protected Overrides Function OnMouseEnter(ByVal eventArgs As MouseEventArgs) As Boolean
            ' Allow other components to process this event by not returning true.
            mouseDown = False
            Return False
        End Function

        Protected Overrides Function OnMouseHover(ByVal eventArgs As MouseEventArgs) As Boolean
            ' Allow other components to process this event by not returning true.
            mouseDown = False
            Return False
        End Function

        Protected Overrides Function OnMouseLeave() As Boolean
            ' Allow other components to process this event by not returning true.
            mouseDown = False
            Return False
        End Function

        Protected Overrides Function OnMouseWheel(ByVal eventArgs As MouseEventArgs) As Boolean
            mouseDown = False
            Return True
        End Function

        Protected Overrides Function OnMouseCaptureChanged() As Boolean
            ' Allow other components to process this event by not returning true.
            mouseDown = False
            Return False
        End Function

        Protected Overrides Function OnDragEnter(ByVal eventArgs As DragEventArgs) As Boolean
            Return True
        End Function

        Protected Overrides Function OnDragOver(ByVal eventArgs As DragEventArgs) As Boolean
            Return True
        End Function

        Protected Overrides Function OnDragLeave() As Boolean
            Return True
        End Function

        Protected Overrides Function OnDragDrop(ByVal eventArgs As DragEventArgs) As Boolean
            Return True
        End Function

        Protected Overrides Function OnGiveFeedback(ByVal gfbevent As GiveFeedbackEventArgs) As Boolean
            Return True
        End Function

        Protected Overrides Function OnQueryContinueDrag(ByVal qcdevent As QueryContinueDragEventArgs) As Boolean
            Return True
        End Function

        Protected Overrides Function OnKeyDown(ByVal eventArgs As KeyEventArgs) As Boolean
            If eventArgs.KeyCode = Keys.Delete Then
                Dim selectionService As ISelectionService = CType(serviceProvider.GetService(GetType(ISelectionService)), ISelectionService)
                If selectionService IsNot Nothing AndAlso TypeOf selectionService.PrimarySelection Is CodeActivity Then
                    Dim codeActivityComponent As CodeActivity = CType(selectionService.PrimarySelection, CodeActivity)
                    Dim parentActivity As CompositeActivity = codeActivityComponent.Parent
                    If parentActivity IsNot Nothing Then
                        parentActivity.Activities.Remove(codeActivityComponent)
                        Me.ParentView.Update()
                    End If
                    loader.RemoveActivityFromDesigner(codeActivityComponent)
                End If
            End If
            Return True
        End Function

        Protected Overrides Function OnKeyUp(ByVal eventArgs As KeyEventArgs) As Boolean
            Return True
        End Function

        Protected Overrides Function OnShowContextMenu(ByVal menuPoint As Point) As Boolean
            Return True
        End Function

#End Region

    End Class