Export (0) Print
Expand All

ContextMenuProvider Class

Defines a set of menu items that are shown in a context menu.

Namespace:  Microsoft.Windows.Design.Interaction
Assembly:  Microsoft.Windows.Design.Extensibility (in Microsoft.Windows.Design.Extensibility.dll)

public abstract class ContextMenuProvider : FeatureProvider

Inherit from the ContextMenuProvider class when you want to add a context menu item to a particular context menu. By applying policies, such as the PrimarySelectionPolicy and the SelectionParentPolicy, you can control when the context menu provider is created.

The existence of ContextMenuProvider is temporary. Do not assume that it will persistent for long periods of time.

The following code example shows how to derive a custom type from the PrimarySelectionContextMenuProvider class. The derived type implements a custom context menu, which sets the Background property of a control at design time. For more information, see Walkthrough: Creating a MenuAction.

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Windows.Design.Interaction;
using System.Windows;
using Microsoft.Windows.Design.Model;
using System.Windows.Controls;
using System.Windows.Media;

namespace SliderAdornerLib
{
    // The CustomContextMenuProvider class provides two context menu items 
    // at design time. These are implemented with the MenuAction class. 
    class CustomContextMenuProvider : PrimarySelectionContextMenuProvider
    {
        private MenuAction setBackgroundToBlueMenuAction;
        private MenuAction clearBackgroundMenuAction;

        // The provider's constructor sets up the MenuAction objects  
        // and the the MenuGroup which holds them. 
        public CustomContextMenuProvider()
        {   
            // Set up the MenuAction which sets the control's  
            // background to Blue.
            setBackgroundToBlueMenuAction = new MenuAction("Blue");
            setBackgroundToBlueMenuAction.Checkable = true;
            setBackgroundToBlueMenuAction.Execute += 
                new EventHandler<MenuActionEventArgs>(SetBackgroundToBlue_Execute);

            // Set up the MenuAction which sets the control's  
            // background to its default value.
            clearBackgroundMenuAction = new MenuAction("Cleared");
            clearBackgroundMenuAction.Checkable = true;
            clearBackgroundMenuAction.Execute += 
                new EventHandler<MenuActionEventArgs>(ClearBackground_Execute);

            // Set up the MenuGroup which holds the MenuAction items.
            MenuGroup backgroundFlyoutGroup = 
                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);
            this.Items.Add(backgroundFlyoutGroup);

            // The UpdateItemStatus event is raised immediately before  
            // this provider shows its tabs, which provides the opportunity  
            // to set states.
            UpdateItemStatus += 
                new EventHandler<MenuActionEventArgs>(
                    CustomContextMenuProvider_UpdateItemStatus);
        }

        // 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. 
        void CustomContextMenuProvider_UpdateItemStatus(
            object sender, 
            MenuActionEventArgs e)
        {
            // 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. 
            ModelItem selectedControl = e.Selection.PrimarySelection;

            // Get the value of the Background property from the ModelItem.
            ModelProperty backgroundProperty = 
                selectedControl.Properties[Control.BackgroundProperty];

            // Set the MenuAction items appropriately. 
            if (!backgroundProperty.IsSet)
            {
                clearBackgroundMenuAction.Checked = true;
                clearBackgroundMenuAction.Enabled = false;
            }
            else if (backgroundProperty.ComputedValue == Brushes.Blue)
            {
                setBackgroundToBlueMenuAction.Checked = true;
                setBackgroundToBlueMenuAction.Enabled = false;
            }
        }

        // The following method handles the Execute event.  
        // It sets the Background property to its default value. 
        void ClearBackground_Execute(
            object sender, 
            MenuActionEventArgs e)
        {
            ModelItem selectedControl = e.Selection.PrimarySelection;
            selectedControl.Properties[Control.BackgroundProperty].ClearValue();
        }

        // The following method handles the Execute event.  
        // It sets the Background property to Brushes.Blue. 
        void SetBackgroundToBlue_Execute(
            object sender, 
            MenuActionEventArgs e)
        {
            ModelItem selectedControl = e.Selection.PrimarySelection;
            selectedControl.Properties[Control.BackgroundProperty].SetValue(Brushes.Blue);
        }
    }
}

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Community Additions

ADD
Show:
© 2014 Microsoft