WorkflowDesignerMessageFilter 类
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。
注意
The System.Workflow.* types are deprecated. Instead, please use the new types from System.Activities.*
为所有工作流消息筛选器提供基类。
public ref class WorkflowDesignerMessageFilter abstract : IDisposable
public abstract class WorkflowDesignerMessageFilter : IDisposable
[System.Obsolete("The System.Workflow.* types are deprecated. Instead, please use the new types from System.Activities.*")]
public abstract class WorkflowDesignerMessageFilter : IDisposable
type WorkflowDesignerMessageFilter = class
interface IDisposable
[<System.Obsolete("The System.Workflow.* types are deprecated. Instead, please use the new types from System.Activities.*")>]
type WorkflowDesignerMessageFilter = class
interface IDisposable
Public MustInherit Class WorkflowDesignerMessageFilter
Implements IDisposable
- 继承
-
WorkflowDesignerMessageFilter
- 属性
- 实现
示例
下面的代码示例演示一个从 WorkflowDesignerMessageFilter 中派生的自定义设计器消息筛选器。 名为 CustomMessageFilter
的类将重写它的许多基类方法,其中包括 OnMouseDown、OnMouseMove、OnMouseUp、OnMouseDoubleClick、OnMouseEnter、OnMouseHover、OnMouseLeave、OnDragEnter、OnDragOver 和 OnKeyDown。
此代码示例摘自 DesignerShell.cs 文件中的基本设计器宿主 SDK 示例。 有关详细信息,请参阅 基本设计器托管。
internal sealed class CustomMessageFilter : WorkflowDesignerMessageFilter
{
#region Members and Constructor
private bool mouseDown;
private IServiceProvider serviceProvider;
private WorkflowView workflowView;
private WorkflowDesignerLoader loader;
public CustomMessageFilter(IServiceProvider provider, WorkflowView workflowView, WorkflowDesignerLoader loader)
{
this.serviceProvider = provider;
this.workflowView = workflowView;
this.loader = loader;
}
#endregion
#region MessageFilter Overridables
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 (mouseDown)
{
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.
mouseDown = false;
return false;
}
protected override bool OnMouseDoubleClick(MouseEventArgs eventArgs)
{
mouseDown = false;
return true;
}
protected override bool OnMouseEnter(MouseEventArgs eventArgs)
{
//Allow other components to process this event by not returning true.
mouseDown = false;
return false;
}
protected override bool OnMouseHover(MouseEventArgs eventArgs)
{
//Allow other components to process this event by not returning true.
mouseDown = false;
return false;
}
protected override bool OnMouseLeave()
{
//Allow other components to process this event by not returning true.
mouseDown = false;
return false;
}
protected override bool OnMouseWheel(MouseEventArgs eventArgs)
{
mouseDown = false;
return true;
}
protected override bool OnMouseCaptureChanged()
{
//Allow other components to process this event by not returning true.
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 OnKeyDown(KeyEventArgs eventArgs)
{
if (eventArgs.KeyCode == Keys.Delete)
{
ISelectionService selectionService = (ISelectionService)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();
}
loader.RemoveActivityFromDesigner(codeActivityComponent);
}
}
return true;
}
protected override bool OnKeyUp(KeyEventArgs eventArgs)
{
return true;
}
protected override bool OnShowContextMenu(Point menuPoint)
{
return true;
}
#endregion
}
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
注解
注意
本材料讨论的类型和命名空间已废弃不用。 有关详细信息,请参阅 Windows Workflow Foundation 4.5 中弃用的类型。
工作流设计器提供一个 Strategy
设计模式来创建可替换的消息筛选器对象以处理事件。
从 WorkflowDesignerMessageFilter 类中进行派生以创建可响应工作流设计器事件(如拖动操作、布局和绘画操作以及其他设计器事件)的消息筛选器。 若要向消息筛选器链添加自定义消息筛选器,请对 AddDesignerMessageFilter 调用 WorkflowView,或重写自定义根活动的 MessageFilters 虚拟属性并向从基类中返回的集合添加自定义消息筛选器。
构造函数
WorkflowDesignerMessageFilter() |
已过时.
在派生类中实现时,初始化 WorkflowDesignerMessageFilter 的实例。 |
属性
MessageHitTestContext |
已过时.
获取描述 HitTestInfo 的上下文的 WorkflowDesignerMessageFilter。 |
ParentView |
已过时.
|