WorkflowView.AddDesignerMessageFilter(WorkflowDesignerMessageFilter) 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
public:
void AddDesignerMessageFilter(System::Workflow::ComponentModel::Design::WorkflowDesignerMessageFilter ^ designerMessageFilter);
public void AddDesignerMessageFilter (System.Workflow.ComponentModel.Design.WorkflowDesignerMessageFilter designerMessageFilter);
member this.AddDesignerMessageFilter : System.Workflow.ComponentModel.Design.WorkflowDesignerMessageFilter -> unit
Public Sub AddDesignerMessageFilter (designerMessageFilter As WorkflowDesignerMessageFilter)
参数
- designerMessageFilter
- WorkflowDesignerMessageFilter
示例
在下面的示例中,创建了一个 WorkflowDesignerLoader,并将 WorkflowView 对象与工作流设计图面相关联。 为了检索消息的通知,创建了一个 WorkflowDesignerMessageFilter 并将其添加到了 WorkflowView 对象。
此代码示例摘自 WorkflowViewWrapper.cs 文件中的 Outlook 工作流向导 SDK 示例。 有关详细信息,请参阅 Outlook 工作流向导示例。
public WorkflowViewWrapper()
{
this.loader = new Loader();
// Create a Workflow Design Surface
this.surface = new DesignSurface();
this.surface.BeginLoad(this.loader);
// Get the Workflow Designer Host
this.Host = this.surface.GetService(typeof(IDesignerHost)) as IDesignerHost;
if (this.Host == null)
return;
// Create a Sequential Workflow by using the Workflow Designer Host
SequentialWorkflow = (SequentialWorkflowActivity)Host.CreateComponent(typeof(SequentialWorkflowActivity));
SequentialWorkflow.Name = "CustomOutlookWorkflow";
// Create a Workflow View on the Workflow Design Surface
this.workflowView = new WorkflowView(this.surface as IServiceProvider);
// Add a message filter to the workflow view, to support panning
MessageFilter filter = new MessageFilter(this.surface as IServiceProvider, this.workflowView);
this.workflowView.AddDesignerMessageFilter(filter);
// Activate the Workflow View
this.Host.Activate();
this.workflowView.Dock = DockStyle.Fill;
this.Controls.Add(workflowView);
this.Dock = DockStyle.Fill;
}
Public Sub New()
Me.loaderValue = New Loader()
' Create a Workflow Design Surface
Me.surface = New DesignSurface()
Me.surface.BeginLoad(Me.loaderValue)
' Get the Workflow Designer Host
If Me.surface.GetService(GetType(IDesignerHost)) IsNot Nothing AndAlso TypeOf Me.surface.GetService(GetType(IDesignerHost)) Is IDesignerHost Then
Me.Host = CType(Me.surface.GetService(GetType(IDesignerHost)), IDesignerHost)
Else
Return
End If
' Create a Sequential Workflow by using the Workflow Designer Host
SequentialWorkflow = CType(Host.CreateComponent(GetType(SequentialWorkflowActivity)), SequentialWorkflowActivity)
SequentialWorkflow.Name = "CustomOutlookWorkflow"
' Create a Workflow View on the Workflow Design Surface
Me.workflowView = New WorkflowView(CType(Me.surface, IServiceProvider))
' Add a message filter to the workflow view, to support panning
Dim filter As MessageFilter = New MessageFilter(CType(Me.surface, IServiceProvider), Me.workflowView)
Me.workflowView.AddDesignerMessageFilter(filter)
' Activate the Workflow View
Me.Host.Activate()
Me.workflowView.Dock = DockStyle.Fill
Me.Controls.Add(workflowView)
Me.Dock = DockStyle.Fill
End Sub
在上面的代码中创建的 MessageFilter
对象是从 WorkflowDesignerMessageFilter 类派生的。 通过重写此类的方法,只要在 WorkflowView 对象上发生用户界面事件,就会通知消息筛选器。
internal sealed class MessageFilter : WorkflowDesignerMessageFilter
{
private bool mouseDown;
private IServiceProvider serviceProvider;
private WorkflowView workflowView;
public MessageFilter(IServiceProvider provider, WorkflowView view)
{
this.serviceProvider = provider;
this.workflowView = view;
}
protected override bool OnMouseDown(MouseEventArgs eventArgs)
{
// Allow other components to process this event by not returning true.
this.mouseDown = true;
return false;
}
protected override bool OnMouseMove(MouseEventArgs eventArgs)
{
// Allow other components to process this event by not returning true.
if (this.mouseDown)
{
this.workflowView.ScrollPosition = new Point(eventArgs.X, eventArgs.Y);
}
return false;
}
protected override bool OnMouseUp(MouseEventArgs eventArgs)
{
// Allow other components to process this event by not returning true.
this.mouseDown = false;
return false;
}
protected override bool OnMouseDoubleClick(MouseEventArgs eventArgs)
{
this.mouseDown = false;
return true;
}
protected override bool OnMouseEnter(MouseEventArgs eventArgs)
{
// Allow other components to process this event by not returning true.
this.mouseDown = false;
return false;
}
protected override bool OnMouseHover(MouseEventArgs eventArgs)
{
// Allow other components to process this event by not returning true.
this.mouseDown = false;
return false;
}
protected override bool OnMouseLeave()
{
// Allow other components to process this event by not returning true.
this.mouseDown = false;
return false;
}
protected override bool OnMouseWheel(MouseEventArgs eventArgs)
{
this.mouseDown = false;
return true;
}
protected override bool OnMouseCaptureChanged()
{
// Allow other components to process this event by not returning true.
this.mouseDown = false;
return false;
}
protected override bool OnDragEnter(DragEventArgs eventArgs)
{
return true;
}
protected override bool OnDragOver(DragEventArgs eventArgs)
{
return true;
}
protected override bool OnDragLeave()
{
return true;
}
protected override bool OnDragDrop(DragEventArgs eventArgs)
{
return true;
}
protected override bool OnGiveFeedback(GiveFeedbackEventArgs gfbevent)
{
return true;
}
protected override bool OnQueryContinueDrag(QueryContinueDragEventArgs qcdevent)
{
return true;
}
protected override bool OnKeyUp(KeyEventArgs eventArgs)
{
return true;
}
protected override bool OnShowContextMenu(Point menuPoint)
{
return true;
}
protected override bool OnKeyDown(KeyEventArgs eventArgs)
{
if (eventArgs.KeyCode == Keys.Delete)
{
ISelectionService selectionService = (ISelectionService)this.serviceProvider.GetService(typeof(ISelectionService));
if (selectionService != null && selectionService.PrimarySelection is CodeActivity)
{
CodeActivity codeActivityComponent = (CodeActivity)selectionService.PrimarySelection;
CompositeActivity parentActivity = codeActivityComponent.Parent;
if (parentActivity != null)
{
parentActivity.Activities.Remove(codeActivityComponent);
this.ParentView.Update();
}
}
}
return true;
}
}
Friend Class MessageFilter
Inherits WorkflowDesignerMessageFilter
Private mouseDown As Boolean
Private serviceProvider As IServiceProvider
Private workflowView As WorkflowView
Public Sub New(ByVal provider As IServiceProvider, ByVal view As WorkflowView)
Me.serviceProvider = provider
Me.workflowView = view
End Sub
Protected Overrides Function OnMouseDown(ByVal eventArgs As System.Windows.Forms.MouseEventArgs) As Boolean
' Allow other components to process this event by not returning true.
Me.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 (Me.mouseDown) Then
Me.workflowView.ScrollPosition = New Point(eventArgs.X, eventArgs.Y)
End If
Return False
End Function
Protected Overrides Function OnMouseUp(ByVal eventArgs As System.Windows.Forms.MouseEventArgs) As Boolean
' Allow other components to process this event by not returning true.
Me.mouseDown = False
Return False
End Function
Protected Overrides Function OnMouseDoubleClick(ByVal eventArgs As System.Windows.Forms.MouseEventArgs) As Boolean
Me.mouseDown = False
Return True
End Function
Protected Overrides Function OnMouseEnter(ByVal eventArgs As System.Windows.Forms.MouseEventArgs) As Boolean
' Allow other components to process this event by not returning true.
Me.mouseDown = False
Return False
End Function
Protected Overrides Function OnMouseHover(ByVal eventArgs As System.Windows.Forms.MouseEventArgs) As Boolean
' Allow other components to process this event by not returning true.
Me.mouseDown = False
Return False
End Function
Protected Overrides Function OnMouseLeave() As Boolean
' Allow other components to process this event by not returning true.
Me.mouseDown = False
Return False
End Function
Protected Overrides Function OnMouseWheel(ByVal eventArgs As System.Windows.Forms.MouseEventArgs) As Boolean
Me.mouseDown = False
Return True
End Function
Protected Overrides Function OnMouseCaptureChanged() As Boolean
' Allow other components to process this event by not returning true.
Me.mouseDown = False
Return False
End Function
Protected Overrides Function OnDragEnter(ByVal eventArgs As System.Windows.Forms.DragEventArgs) As Boolean
Return True
End Function
Protected Overrides Function OnDragOver(ByVal eventArgs As System.Windows.Forms.DragEventArgs) As Boolean
Return True
End Function
Protected Overrides Function OnDragLeave() As Boolean
Return True
End Function
Protected Overrides Function OnDragDrop(ByVal eventArgs As System.Windows.Forms.DragEventArgs) As Boolean
Return True
End Function
Protected Overrides Function OnGiveFeedback(ByVal eventArgs As System.Windows.Forms.GiveFeedbackEventArgs) As Boolean
Return True
End Function
Protected Overrides Function OnQueryContinueDrag(ByVal eventArgs As System.Windows.Forms.QueryContinueDragEventArgs) As Boolean
Return True
End Function
Protected Overrides Function OnKeyUp(ByVal eventArgs As System.Windows.Forms.KeyEventArgs) As Boolean
Return True
End Function
Protected Overrides Function OnShowContextMenu(ByVal screenMenuPoint As System.Drawing.Point) As Boolean
Return True
End Function
Protected Overrides Function OnKeyDown(ByVal eventArgs As System.Windows.Forms.KeyEventArgs) As Boolean
If eventArgs.KeyCode = Keys.Delete Then
Dim selectionService As ISelectionService = CType(Me.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
End If
End If
Return True
End Function
End Class
注解
WorkflowDesignerMessageFilter 是一个组件,它处理来自 WorkflowView 的消息。
使用 Strategy
设计模式,WorkflowView 会将消息传递到 WorkflowDesignerMessageFilter 以进行处理。
鼠标事件、键盘事件、绘画和布局事件传递到与 WorkflowDesignerMessageFilter 关联的 WorkflowView。
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