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IPropertyValueUIService Interface

Provides an interface to manage the images, ToolTips, and event handlers for the properties of a component displayed in a property browser.

Namespace:  System.Drawing.Design
Assembly:  System.Drawing (in System.Drawing.dll)

'Declaration
Public Interface IPropertyValueUIService
'Usage
Dim instance As IPropertyValueUIService

A component can use the IPropertyValueUIService interface to provide PropertyValueUIItem objects for any properties of the component. A PropertyValueUIItem associated with a property can provide an image, a ToolTip and an event handler for the event that is raised when the image associated with the property is clicked.

The IPropertyValueUIService interface provides methods to add, remove, and retrieve PropertyValueUIHandler delegates to or from an internal list. When the properties of a component are displayed in a property browser, each PropertyValueUIHandler in the list is given an opportunity to provide a PropertyValueUIItem for each property of the component.

When a property browser is set to display the properties of an object, it calls the GetPropertyUIValueItems method of this interface for each property of the component, passing a PropertyDescriptor that represents the property. The GetPropertyUIValueItems method calls each PropertyValueUIHandler that has been added to the service. Each PropertyValueUIHandler can add a PropertyValueUIItem to the ArrayList parameter passed in the valueUIItemList parameter to supply UI items for the property represented by the PropertyDescriptor passed in the propDesc parameter.

A PropertyValueUIItem can contain an image to display next to the property name, a ToolTip string, and an event handler to invoke when an image associated with the property is double-clicked.

The following code example creates a component that obtains an instance of the IPropertyValueUIService interface and adds a PropertyValueUIHandler to the service. The handler provides a PropertyValueUIItem object for any properties of the component named HorizontalMargin or VerticalMargin. The PropertyValueUIItem for these properties provides an image, a ToolTip, and an event handler that displays a message box when the image for the property is clicked. The image and the ToolTip are displayed in a PropertyGrid when the grid is showing these properties of the component.

Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Drawing.Design
Imports System.IO
Imports System.Runtime.Serialization
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Windows.Forms
Imports System.Windows.Forms.Design

' This component obtains the IPropertyValueUIService and adds a 
' PropertyValueUIHandler that provides PropertyValueUIItem objects 
' which provide an image, tooltip and invoke event handler to 
' any properties named HorizontalMargin and VerticalMargin,  
' such as the example integer properties on this component.     
Public Class PropertyUIComponent
    Inherits System.ComponentModel.Component

    ' Example property for which to provide PropertyValueUIItem. 
    Public Property HorizontalMargin() As Integer 
        Get 
            Return hMargin
        End Get 
        Set(ByVal Value As Integer)
            hMargin = Value
        End Set 
    End Property 

    ' Example property for which to provide PropertyValueUIItem.        
    Public Property VerticalMargin() As Integer 
        Get 
            Return vMargin
        End Get 
        Set(ByVal Value As Integer)
            vMargin = Value
        End Set 
    End Property 

    ' Field storing the value of the HorizontalMargin property 
    Private hMargin As Integer 

    ' Field storing the value of the VerticalMargin property 
    Private vMargin As Integer 

    ' Base64-encoded serialized image data for image icon. 
    Private imageBlob1 As String = "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" 

    ' Constructor. 
    Public Sub New(ByVal container As System.ComponentModel.IContainer)
        If (container IsNot Nothing) Then
            container.Add(Me)
        End If
        hMargin = 0
        vMargin = 0
    End Sub 

    ' Default component constructor that specifies no container. 
    Public Sub New()
        MyClass.New(Nothing)
    End Sub 

    ' PropertyValueUIHandler delegate that provides PropertyValueUIItem 
    ' objects to any properties named HorizontalMargin or VerticalMargin. 
    Private Sub marginPropertyValueUIHandler(ByVal context As System.ComponentModel.ITypeDescriptorContext, ByVal propDesc As System.ComponentModel.PropertyDescriptor, ByVal itemList As ArrayList)
        ' A PropertyValueUIHandler added to the IPropertyValueUIService 
        ' is queried once for each property of a component and passed 
        ' a PropertyDescriptor that represents the characteristics of  
        ' the property when the Properties window is set to a new  
        ' component. A PropertyValueUIHandler can determine whether  
        ' to add a PropertyValueUIItem for the object to its ValueUIItem  
        ' list depending on the values of the PropertyDescriptor. 
        If propDesc.DisplayName.Equals("HorizontalMargin") Then 
            Dim img As Image = DeserializeFromBase64Text(imageBlob1)
            itemList.Add(New PropertyValueUIItem(img, New PropertyValueUIItemInvokeHandler(AddressOf Me.marginInvoke), "Test ToolTip"))
        End If 
        If propDesc.DisplayName.Equals("VerticalMargin") Then 
            Dim img As Image = DeserializeFromBase64Text(imageBlob1)
            img.RotateFlip(RotateFlipType.Rotate90FlipNone)
            itemList.Add(New PropertyValueUIItem(img, New PropertyValueUIItemInvokeHandler(AddressOf Me.marginInvoke), "Test ToolTip"))
        End If 
    End Sub 

    ' Invoke handler associated with the PropertyValueUIItem objects  
    ' provided by the marginPropertyValueUIHandler. 
    Private Sub marginInvoke(ByVal context As System.ComponentModel.ITypeDescriptorContext, ByVal propDesc As System.ComponentModel.PropertyDescriptor, ByVal item As PropertyValueUIItem)
        MessageBox.Show("Test invoke message box")
    End Sub 

    ' Component.Site override to add the marginPropertyValueUIHandler 
    ' when the component is sited, and to remove it when the site is  
    ' set to null. 
    Public Overrides Property Site() As System.ComponentModel.ISite
        Get 
            Return MyBase.Site
        End Get 
        Set(ByVal Value As System.ComponentModel.ISite)
            If (Value IsNot Nothing) Then 
                MyBase.Site = Value
                Dim uiService As IPropertyValueUIService = CType(Me.GetService(GetType(IPropertyValueUIService)), IPropertyValueUIService)
                If (uiService IsNot Nothing) Then
                    uiService.AddPropertyValueUIHandler(New PropertyValueUIHandler(AddressOf Me.marginPropertyValueUIHandler))
                End If 
            Else 
                Dim uiService As IPropertyValueUIService = CType(Me.GetService(GetType(IPropertyValueUIService)), IPropertyValueUIService)
                If (uiService IsNot Nothing) Then
                    uiService.RemovePropertyValueUIHandler(New PropertyValueUIHandler(AddressOf Me.marginPropertyValueUIHandler))
                End If 
                MyBase.Site = Value
            End If 
        End Set 
    End Property 

    ' This method can be used to retrieve an Image from a block  
    ' of Base64-encoded text. 
    Private Function DeserializeFromBase64Text(ByVal [text] As String) As Image
        Dim img As Image = Nothing 
        Dim memBytes As Byte() = Convert.FromBase64String([text])
        Dim formatter As New BinaryFormatter()
        Dim stream As New MemoryStream(memBytes)
        img = CType(formatter.Deserialize(stream), Image)
        stream.Close()
        Return img
    End Function 

End Class

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
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