Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing
Imports System.Drawing.Design
Imports System.Data
Imports System.Diagnostics
Imports System.Reflection
Imports System.Windows.Forms
' Provides an example control that functions in design mode to
' demonstrate use of the IToolboxService to list and select toolbox
' categories and items, and to add components or controls
' to the parent form using code.
<DesignerAttribute(GetType(WindowMessageDesigner), GetType(IDesigner))> _
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Public Class IToolboxServiceControl
Inherits System.Windows.Forms.UserControl
Private WithEvents listBox1 As System.Windows.Forms.ListBox
Private listBox2 As System.Windows.Forms.ListBox
Private toolboxService As IToolboxService = Nothing
Private tools As ToolboxItemCollection
Private controlSpacingMultiplier As Integer
Public Sub New()
InitializeComponent()
AddHandler listBox2.DoubleClick, AddressOf Me.CreateComponent
controlSpacingMultiplier = 0
End Sub
' Obtain or reset IToolboxService reference on each siting of control.
Public Overrides Property Site() As System.ComponentModel.ISite
Get
Return MyBase.Site
End Get
Set(ByVal Value As System.ComponentModel.ISite)
MyBase.Site = Value
' If the component was sited, attempt to obtain
' an IToolboxService instance.
If (MyBase.Site IsNot Nothing) Then
toolboxService = CType(Me.GetService(GetType(IToolboxService)), IToolboxService)
' If an IToolboxService instance was located, update the
' category list.
If (toolboxService IsNot Nothing) Then
UpdateLists()
End If
Else
toolboxService = Nothing
End If
End Set
End Property
' Updates the list of categories and the list of items in the
' selected category.
Private Sub UpdateLists()
If (toolboxService IsNot Nothing) Then
RemoveHandler listBox1.SelectedIndexChanged, AddressOf Me.UpdateSelectedCategory
RemoveHandler listBox2.SelectedIndexChanged, AddressOf Me.UpdateSelectedItem
listBox1.Items.Clear()
Dim i As Integer
For i = 0 To toolboxService.CategoryNames.Count - 1
listBox1.Items.Add(toolboxService.CategoryNames(i))
If toolboxService.CategoryNames(i) = toolboxService.SelectedCategory Then
listBox1.SelectedIndex = i
tools = toolboxService.GetToolboxItems(toolboxService.SelectedCategory)
listBox2.Items.Clear()
Dim j As Integer
For j = 0 To tools.Count - 1
listBox2.Items.Add(tools(j).DisplayName)
Next j
End If
Next i
AddHandler Me.listBox1.SelectedIndexChanged, AddressOf Me.UpdateSelectedCategory
AddHandler Me.listBox2.SelectedIndexChanged, AddressOf Me.UpdateSelectedItem
End If
End Sub
' Sets the selected category when a category is clicked in the
' category list.
Private Sub UpdateSelectedCategory(ByVal sender As Object, ByVal e As System.EventArgs) Handles listBox1.SelectedIndexChanged
If (toolboxService IsNot Nothing) Then
toolboxService.SelectedCategory = CStr(listBox1.SelectedItem)
UpdateLists()
End If
End Sub
' Sets the selected item when an item is clicked in the item list.
Private Sub UpdateSelectedItem(ByVal sender As Object, ByVal e As System.EventArgs)
If (toolboxService IsNot Nothing) Then
If listBox1.SelectedIndex <> -1 Then
If CStr(listBox1.SelectedItem) = toolboxService.SelectedCategory Then
toolboxService.SetSelectedToolboxItem(tools(listBox2.SelectedIndex))
Else
UpdateLists()
End If
End If
End If
End Sub
' Creates a control from a double-clicked toolbox item and adds
' it to the parent form.
Private Sub CreateComponent(ByVal sender As Object, ByVal e As EventArgs)
' Obtains an IDesignerHost service from design environment.
Dim host As IDesignerHost = CType(Me.GetService(GetType(IDesignerHost)), IDesignerHost)
' Gets the project components container. (Windows Forms control
' containment depends on controls collections).
Dim container As IContainer = host.Container
' Identifies the parent Form.
Dim parentForm As System.Windows.Forms.Form = Me.FindForm()
' Retrieves the parent Form's designer host.
Dim parentHost As IDesignerHost = CType(parentForm.Site.GetService(GetType(IDesignerHost)), IDesignerHost)
' Create the components.
Dim comps As IComponent() = Nothing
Try
comps = toolboxService.GetSelectedToolboxItem().CreateComponents(parentHost)
Catch ex As Exception
' Catch and show any exceptions to prevent
' disabling the control's UI.
MessageBox.Show(ex.ToString(), "Exception message")
End Try
If comps Is Nothing Then
Return
End If
' Add any created controls to the parent form's controls
' collection. Note: components are added from the
' ToolboxItem.CreateComponents(IDesignerHost) method.
Dim i As Integer
For i = 0 To comps.Length - 1
If (parentForm IsNot Nothing) AndAlso CType(comps(i), Object).GetType().IsSubclassOf(GetType(System.Windows.Forms.Control)) Then
CType(comps(i), System.Windows.Forms.Control).Location = New Point(20 * controlSpacingMultiplier, 20 * controlSpacingMultiplier)
If controlSpacingMultiplier > 10 Then
controlSpacingMultiplier = 0
Else
controlSpacingMultiplier += 1
End If
parentForm.Controls.Add(CType(comps(i), System.Windows.Forms.Control))
End If
Next i
End Sub
' Displays labels.
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
e.Graphics.DrawString("IToolboxService Control", New Font("Arial", 14), New SolidBrush(Color.Black), 6, 4)
e.Graphics.DrawString("Category List", New Font("Arial", 8), New SolidBrush(Color.Black), 8, 26)
e.Graphics.DrawString("Items in Category", New Font("Arial", 8), New SolidBrush(Color.Black), 208, 26)
e.Graphics.DrawString("(Double-click item to add to parent form)", New Font("Arial", 7), New SolidBrush(Color.Black), 232, 12)
End Sub
Private Sub InitializeComponent()
Me.listBox1 = New System.Windows.Forms.ListBox()
Me.listBox2 = New System.Windows.Forms.ListBox()
Me.SuspendLayout()
Me.listBox1.Anchor = System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left
Me.listBox1.Location = New System.Drawing.Point(8, 41)
Me.listBox1.Name = "listBox1"
Me.listBox1.Size = New System.Drawing.Size(192, 368)
Me.listBox1.TabIndex = 0
Me.listBox2.Anchor = System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left Or System.Windows.Forms.AnchorStyles.Right
Me.listBox2.Location = New System.Drawing.Point(208, 41)
Me.listBox2.Name = "listBox2"
Me.listBox2.Size = New System.Drawing.Size(228, 368)
Me.listBox2.TabIndex = 3
Me.BackColor = System.Drawing.Color.Beige
Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.listBox2, Me.listBox1})
Me.Location = New System.Drawing.Point(500, 400)
Me.Name = "IToolboxServiceControl"
Me.Size = New System.Drawing.Size(442, 422)
Me.ResumeLayout(False)
End Sub
End Class
' This designer passes window messages to the controls at design time.
Public Class WindowMessageDesigner
Inherits System.Windows.Forms.Design.ControlDesigner
Public Sub New()
End Sub
' Window procedure override passes events to control.
<System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
If m.HWnd.Equals(Me.Control.Handle) Then
MyBase.WndProc(m)
Else
Me.DefWndProc(m)
End If
End Sub
End Class