WorkflowMenuCommands.SelectionMenu 字段

定义

命名空间:

System.Workflow.ComponentModel.Design

程序集:

System.Workflow.ComponentModel.dll

可用于访问选择菜单的 CommandID。 此字段为只读。

public: static initonly System::ComponentModel::Design::CommandID ^ SelectionMenu;

public static readonly System.ComponentModel.Design.CommandID SelectionMenu;

 staticval mutable SelectionMenu : System.ComponentModel.Design.CommandID

Public Shared ReadOnly SelectionMenu As CommandID 

字段值

CommandID

示例

下面的示例演示如何创建自定义 MenuCommandService。 在此示例中，当调用 ShowContextMenu 时会创建一个上下文菜单。 在 GetSelectionMenuItems 方法中，使用 WorkflowMenuCommands 类将工作流设计器提供的适当菜单命令与其对应文本相关联。 此操作完成后，将一个事件处理程序与每个命令相关联，以便在选择该命令时，调用相应的 MenuCommand。

internal sealed class WorkflowMenuCommandService : MenuCommandService
{
    public WorkflowMenuCommandService(IServiceProvider serviceProvider)
        : base(serviceProvider)
    {
    }

    public override void ShowContextMenu(CommandID menuID, int x, int y)
    {
        if (menuID == WorkflowMenuCommands.SelectionMenu)
        {
            ContextMenu contextMenu = new ContextMenu();

            foreach (DesignerVerb verb in Verbs)
            {
                MenuItem menuItem = new MenuItem(verb.Text, new EventHandler(OnMenuClicked));
                menuItem.Tag = verb;
                contextMenu.MenuItems.Add(menuItem);
            }

            MenuItem[] items = GetSelectionMenuItems();
            if (items.Length > 0)
            {
                contextMenu.MenuItems.Add(new MenuItem("-"));
                foreach (MenuItem item in items)
                    contextMenu.MenuItems.Add(item);
            }

            WorkflowView workflowView = GetService(typeof(WorkflowView)) as WorkflowView;
            if (workflowView != null)
                contextMenu.Show(workflowView, workflowView.PointToClient(new Point(x, y)));
        }
    }

    private MenuItem[] GetSelectionMenuItems()
    {
        List<MenuItem> menuItems = new List<MenuItem>();

        bool addMenuItems = true;
        ISelectionService selectionService = GetService(typeof(ISelectionService)) as ISelectionService;
        if (selectionService != null)
        {
            foreach (object obj in selectionService.GetSelectedComponents())
            {
                if (!(obj is Activity))
                {
                    addMenuItems = false;
                    break;
                }
            }
        }

        if (addMenuItems)
        {
            Dictionary<CommandID, string> selectionCommands = new Dictionary<CommandID, string>();
            selectionCommands.Add(WorkflowMenuCommands.Cut, "Cut");
            selectionCommands.Add(WorkflowMenuCommands.Copy, "Copy");
            selectionCommands.Add(WorkflowMenuCommands.Paste, "Paste");
            selectionCommands.Add(WorkflowMenuCommands.Delete, "Delete");
            selectionCommands.Add(WorkflowMenuCommands.Collapse, "Collapse");
            selectionCommands.Add(WorkflowMenuCommands.Expand, "Expand");
            selectionCommands.Add(WorkflowMenuCommands.Disable, "Disable");
            selectionCommands.Add(WorkflowMenuCommands.Enable, "Enable");

            foreach (CommandID id in selectionCommands.Keys)
            {
                MenuCommand command = FindCommand(id);
                if (command != null)
                {
                    MenuItem menuItem = new MenuItem(selectionCommands[id], new EventHandler(OnMenuClicked));
                    menuItem.Tag = command;
                    menuItems.Add(menuItem);
                }
            }
        }

        return menuItems.ToArray();
    }

    private void OnMenuClicked(object sender, EventArgs e)
    {
        MenuItem menuItem = sender as MenuItem;
        if (menuItem != null && menuItem.Tag is MenuCommand)
        {
            MenuCommand command = menuItem.Tag as MenuCommand;
            command.Invoke();
        }
    }
}

Friend NotInheritable Class WorkflowMenuCommandService
    Inherits MenuCommandService
    Public Sub New(ByVal serviceProvider As IServiceProvider)
        MyBase.new(serviceProvider)
    End Sub
    Public Overrides Sub ShowContextMenu(ByVal menuID As CommandID, ByVal x As Integer, ByVal y As Integer)

        If menuID.ID = WorkflowMenuCommands.SelectionMenu.ID Then
            Dim contextMenu As New ContextMenu()

            For Each verb As DesignerVerb In Verbs
                Dim MenuItem As New MenuItem(verb.Text, AddressOf OnMenuClicked)
                MenuItem.Tag = verb
                contextMenu.MenuItems.Add(MenuItem)
            Next

            Dim items As MenuItem() = GetSelectionMenuItems()
            If (items.Length > 0) Then

                contextMenu.MenuItems.Add(New MenuItem("-"))
                For Each item As MenuItem In items
                    contextMenu.MenuItems.Add(item)
                Next

                Dim workflowView As WorkflowView = CType(GetService(GetType(WorkflowView)), WorkflowView)
                If workflowView Is Nothing Then
                    contextMenu.Show(workflowView, workflowView.PointToClient(New Point(x, y)))
                End If
            End If
        End If
    End Sub

    Private Function GetSelectionMenuItems() As MenuItem()

        Dim menuItems As New List(Of MenuItem)()

        Dim addMenuItems As Boolean = True
        Dim selectionService As ISelectionService = CType(GetService(GetType(ISelectionService)), ISelectionService)
        If selectionService IsNot Nothing Then

            For Each obj As Object In selectionService.GetSelectedComponents()
                If Not TypeOf obj Is Activity Then
                    addMenuItems = False
                    Exit For
                End If
            Next
        End If


        If (addMenuItems) Then

            Dim selectionCommands As New Dictionary(Of CommandID, String)()
            selectionCommands.Add(WorkflowMenuCommands.Cut, "Cut")
            selectionCommands.Add(WorkflowMenuCommands.Copy, "Copy")
            selectionCommands.Add(WorkflowMenuCommands.Paste, "Paste")
            selectionCommands.Add(WorkflowMenuCommands.Delete, "Delete")
            selectionCommands.Add(WorkflowMenuCommands.Collapse, "Collapse")
            selectionCommands.Add(WorkflowMenuCommands.Expand, "Expand")
            selectionCommands.Add(WorkflowMenuCommands.Disable, "Disable")
            selectionCommands.Add(WorkflowMenuCommands.Enable, "Enable")

            For Each id As CommandID In selectionCommands.Keys

                Dim command As MenuCommand = FindCommand(id)
                If command IsNot Nothing Then
                    Dim menuItem As New MenuItem(selectionCommands(id), AddressOf OnMenuClicked)
                    menuItem.Tag = command
                    menuItems.Add(menuItem)
                End If
            Next
        End If

        Return menuItems.ToArray()
    End Function

    Private Sub OnMenuClicked(ByVal sender As Object, ByVal e As EventArgs)

        Dim menuItem As MenuItem = CType(sender, MenuItem)
        If menuItem IsNot Nothing And TypeOf menuItem.Tag Is MenuCommand Then
            Dim command As MenuCommand = CType(menuItem.Tag, MenuCommand)
            command.Invoke()
        End If
    End Sub
End Class

若要启用此服务，请调用 AddService 类中 LoaderHost 属性的 WorkflowDesignerLoader 方法，如下面的示例所示。

protected override void Initialize()
{
    base.Initialize();

    IDesignerLoaderHost host = this.LoaderHost;
    if (host != null)
    {
        host.RemoveService(typeof(IIdentifierCreationService));
        host.AddService(typeof(IIdentifierCreationService), new IdentifierCreationService(host));
        host.AddService(typeof(IMenuCommandService), new WorkflowMenuCommandService(host));
        host.AddService(typeof(IToolboxService), new Toolbox(host));
        TypeProvider typeProvider = new TypeProvider(host);
        typeProvider.AddAssemblyReference(typeof(string).Assembly.Location);
        host.AddService(typeof(ITypeProvider), typeProvider, true);
        host.AddService(typeof(IEventBindingService), new EventBindingService());
    }
}

Protected Overrides Sub Initialize()
    MyBase.Initialize()

    Dim host As IDesignerLoaderHost = Me.LoaderHost
    If host IsNot Nothing Then
        host.RemoveService(GetType(IIdentifierCreationService))
        host.AddService(GetType(IIdentifierCreationService), New IdentifierCreationService(host))
        host.AddService(GetType(IMenuCommandService), New WorkflowMenuCommandService(host))
        host.AddService(GetType(IToolboxService), New Toolbox(host))
        Dim typeProvider As New TypeProvider(host)
        typeProvider.AddAssemblyReference(GetType(String).Assembly.Location)
        host.AddService(GetType(ITypeProvider), typeProvider, True)
        host.AddService(GetType(IEventBindingService), New EventBindingService())
    End If
End Sub

注解

选择菜单通常用于管理工作流中的选择。