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WindowsFormsComponentEditor Class

Provides a base class for editors that use a modal dialog to display a properties page similar to an ActiveX control's property page.

Namespace:  System.Windows.Forms.Design
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

'Declaration
<PermissionSetAttribute(SecurityAction.InheritanceDemand, Name := "FullTrust")> _
Public MustInherit Class WindowsFormsComponentEditor _
	Inherits ComponentEditor
'Usage
Dim instance As WindowsFormsComponentEditor

The following code example demonstrates an example WindowsFormsComponentEditor implementation.

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

' This example demonstrates how to implement a component editor that hosts  
' component pages and associate it with a component. This example also  
' demonstrates how to implement a component page that provides a panel-based  
' control system and Help keyword support. 
' The ExampleComponentEditor displays two ExampleComponentEditorPage pages. 
Public Class ExampleComponentEditor
    Inherits System.Windows.Forms.Design.WindowsFormsComponentEditor

    ' This method override returns an type array containing the type of  
    ' each component editor page to display. 
    Protected Overrides Function GetComponentEditorPages() As Type()
        Return New Type() {GetType(ExampleComponentEditorPage), GetType(ExampleComponentEditorPage)}
    End Function 

    ' This method override returns the index of the page to display when the  
    ' component editor is first displayed. 
    Protected Overrides Function GetInitialComponentEditorPageIndex() As Integer 
        Return 1
    End Function 

    Public Overloads Overrides Function EditComponent(ByVal context As System.ComponentModel.ITypeDescriptorContext, ByVal component As Object) As Boolean 

    End Function 
End Class 

' This example component editor page type provides an example  
' ComponentEditorPage implementation. 
Friend Class ExampleComponentEditorPage
    Inherits System.Windows.Forms.Design.ComponentEditorPage
    Private l1 As Label
    Private b1 As Button
    Private pg1 As PropertyGrid

    ' Base64-encoded serialized image data for the required component editor page icon. 
    Private icondata As String = "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" 

    Public Sub New()
        ' Initialize the page, which inherits from Panel, and its controls. 
        Me.Size = New Size(400, 250)
        Me.Icon = DeserializeIconFromBase64Text(icondata)
        Me.Text = "Example Page"

        b1 = New Button
        b1.Size = New Size(200, 20)
        b1.Location = New Point(200, 0)
        b1.Text = "Set a random background color" 
        AddHandler b1.Click, AddressOf Me.randomBackColor
        Me.Controls.Add(b1)

        l1 = New Label
        l1.Size = New Size(190, 20)
        l1.Location = New Point(4, 2)
        l1.Text = "Example Component Editor Page" 
        Me.Controls.Add(l1)

        pg1 = New PropertyGrid
        pg1.Size = New Size(400, 280)
        pg1.Location = New Point(0, 30)
        Me.Controls.Add(pg1)
    End Sub 

    ' This method indicates that the Help button should be enabled for this  
    ' component editor page. 
    Public Overrides Function SupportsHelp() As Boolean 
        Return True 
    End Function 

    ' This method is called when the Help button for this component editor page is pressed. 
    ' This implementation uses the IHelpService to show the Help topic for a sample keyword. 
    Public Overrides Sub ShowHelp()
        ' The GetSelectedComponent method of a ComponentEditorPage retrieves the 
        ' IComponent associated with the WindowsFormsComponentEditor. 
        Dim selectedComponent As IComponent = Me.GetSelectedComponent()

        ' Retrieve the Site of the component, and return if null. 
        Dim componentSite As ISite = selectedComponent.Site
        If componentSite Is Nothing Then 
            Return 
        End If 
        ' Acquire the IHelpService to display a help topic using a indexed keyword lookup. 
        Dim helpService As IHelpService = CType(componentSite.GetService(GetType(IHelpService)), IHelpService)
        If (helpService IsNot Nothing) Then
            helpService.ShowHelpFromKeyword("System.Windows.Forms.ComboBox")
        End If 
    End Sub 

    ' The LoadComponent method is raised when the ComponentEditorPage is displayed. 
    Protected Overrides Sub LoadComponent()
        Me.pg1.SelectedObject = Me.Component
    End Sub 

    ' The SaveComponent method is raised when the WindowsFormsComponentEditor is closing  
    ' or the current ComponentEditorPage is closing. 
    Protected Overrides Sub SaveComponent()
    End Sub 

    ' If the associated component is a Control, this method sets the BackColor to a random color. 
    ' This method is invoked by the button on this ComponentEditorPage. 
    Private Sub randomBackColor(ByVal sender As Object, ByVal e As EventArgs)
        If GetType(System.Windows.Forms.Control).IsAssignableFrom(CType(Me.Component, Object).GetType()) Then 
            ' Sets the background color of the Control associated with the 
            ' WindowsFormsComponentEditor to a random color. 
            Dim rnd As New Random
            CType(Me.Component, System.Windows.Forms.Control).BackColor = Color.FromArgb(rnd.Next(255), rnd.Next(255), rnd.Next(255))
            pg1.Refresh()
        End If 
    End Sub 

    ' This method can be used to retrieve an Icon from a block  
    ' of Base64-encoded text. 
    Private Function DeserializeIconFromBase64Text(ByVal [text] As String) As icon
        Dim img As Icon = Nothing 
        Dim memBytes As Byte() = Convert.FromBase64String([text])
        Dim formatter As New BinaryFormatter
        Dim stream As New MemoryStream(memBytes)
        img = CType(formatter.Deserialize(stream), Icon)
        stream.Close()
        Return img
    End Function 
End Class 

' This example control is associated with the ExampleComponentEditor  
' through the following EditorAttribute.
<EditorAttribute(GetType(ExampleComponentEditor), GetType(ComponentEditor))> _
Public Class ExampleUserControl
    Inherits System.Windows.Forms.UserControl
End Class

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

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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