How to select a control programmatically in design mode - vb.net

Question

Could someone please tell me how to select a control programmatically in design mode.
I tried to create a custom user control in VB.net that consists of two panels.
I want the whole user control to be easily selectable in design mode.
I have included the following sample and tried.
I was able to identify the selected control but can't SELECT it.
I am using visual studio 2015 / windows 10 Pro.
1.Make Project
New Project -> Windows Forms application
-> name : sample -> [OK]
2.Add User Control
Add -> New Item -> User Control -> Name : usrPanel.vb -> [Add]
usrPanel.BorderStyle : FixedSingle
3.Add 2 Panel controls on usrPanel
Add Panel control on usrPanel
name : pnlTitle
pnlTitle.Dock : Top
pnlTitle.BackColor : Maroon
Add one more Panel
name : pnlMain
pnlMain.Dock : Full
4.Modify usrPanel.vb like this
Imports System.ComponentModel
Imports System.Windows.Forms.Design
Imports System.Windows.Forms.Design.Behavior
<Designer(GetType(usrPanelDesigner))>
Public Class usrPanel
End Class
Public Class usrPanelDesigner
Inherits ParentControlDesigner
Private myAdorner As Adorner
Public Overrides Sub Initialize(component As IComponent)
MyBase.Initialize(component)
If (TypeOf MyBase.Control Is usrPanel) Then
MyBase.EnableDesignMode(DirectCast(MyBase.Control, usrPanel).pnlTitle, "Title")
MyBase.EnableDesignMode(DirectCast(MyBase.Control, usrPanel).pnlMain, "Main")
End If
myAdorner = New Adorner()
BehaviorService.Adorners.Add(myAdorner)
myAdorner.Glyphs.Add(New MyGlyph(BehaviorService, Control))
End Sub
End Class
5.Paste this entire sample below.
https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.design.behavior.behavior?redirectedfrom=MSDN&view=netcore-3.1
Class MyGlyph
Inherits Glyph
Private control As Control
Private behaviorSvc As _
System.Windows.Forms.Design.Behavior.BehaviorService
Public Sub New(ByVal behaviorSvc As _
System.Windows.Forms.Design.Behavior.BehaviorService, _
ByVal control As Control)
MyBase.New(New MyBehavior())
Me.behaviorSvc = behaviorSvc
Me.control = control
End Sub
Public Overrides ReadOnly Property Bounds() As Rectangle
Get
' Create a glyph that is 10x10 and sitting
' in the middle of the control. Glyph coordinates
' are in adorner window coordinates, so we must map
' using the behavior service.
Dim edge As Point = behaviorSvc.ControlToAdornerWindow(control)
Dim size As Size = control.Size
Dim center As New Point(edge.X + size.Width / 2, edge.Y + _
size.Height / 2)
Dim bounds1 As New Rectangle(center.X - 5, center.Y - 5, 10, 10)
Return bounds1
End Get
End Property
Public Overrides Function GetHitTest(ByVal p As Point) As Cursor
' GetHitTest is called to see if the point is
' within this glyph. This gives us a chance to decide
' what cursor to show. Returning null from here means
' the mouse pointer is not currently inside of the glyph.
' Returning a valid cursor here indicates the pointer is
' inside the glyph,and also enables our Behavior property
' as the active behavior.
If Bounds.Contains(p) Then
Return Cursors.Hand
End If
Return Nothing
End Function
Public Overrides Sub Paint(ByVal pe As PaintEventArgs)
' Draw our glyph. It is simply a blue ellipse.
pe.Graphics.FillEllipse(Brushes.Blue, Bounds)
End Sub
' By providing our own behavior we can do something interesting
' when the user clicks or manipulates our glyph.
Class MyBehavior
Inherits System.Windows.Forms.Design.Behavior.Behavior
Public Overrides Function OnMouseUp(ByVal g As Glyph, _
ByVal button As MouseButtons) As Boolean
MessageBox.Show("Hey, you clicked the mouse here")
Return True
' indicating we processed this event.
End Function 'OnMouseUp
End Class
End Class
6.After Mouse Clidk I want to select the specified panel
in Design Mode
MessageBox.Show("Hey, you clicked the mouse here")
Change
'MessageBox.Show("Hey, you clicked the mouse here")
Dim myg As MyGlyph = CType(g, MyGlyph)
Dim c As Control = myg.control
c.Select()
c.Focus()
7.Build All
8.Add usrPanel control on Form1
usrPanel was displayed
click header of usrPanel -> header SELECTED
click blue point -> nothing happens
click the right edge of the usrPanel -> The entire panel is SELECTED
How do I get the usrPanel to be SELECTED when the blue point is clicked?

Answer 1

WinForm Designer code is all about using designer services. In this case you need to acquire an instance of the selection service that is manifested through an object that implements the ISelectionService Interface.
You acquire a service instance through an object that implements the IServiceProvider Interface. The Control.Site Property implements the ISite Interface that in turn implements IServiceProvider.
Use the IServiceProvider.GetService(Type) Method to acquire the service and then use the ISelectionService.SetSelectedComponents Method to select the desired component(s).
Public Overrides Function OnMouseUp(g As Glyph, button As MouseButtons) As Boolean
Dim myg As MyGlyph = CType(g, MyGlyph)
Dim c As Control = myg.control
Dim selService As ISelectionService = CType(c.Site.GetService(GetType(ISelectionService)), ISelectionService)
selService?.SetSelectedComponents({c})
Return True
End Function