How can I change one label out of many by right clicking one of them - vb.net

Question

I have some simple code. It changes the BorderStyle property of a Label by right-clicking. Nothing fancy, but still. However, I have twenty labels. Is there a simpler way of doing this instead of "copy-paste" this code 20 times?
Private Sub Label1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) _
Handles Label1.MouseDown
If e.Button = MouseButtons.Right Then
If Label1.BorderStyle = BorderStyle.None Then
Label1.BorderStyle = BorderStyle.FixedSingle
Else
Label1.BorderStyle = BorderStyle.None
End If
End If
End Sub
Private Sub Label2_MouseDown...
...
End Sub

Answer 1

You could either create a custom control which inherits from Label and has the behaviour you want, or you could write a handler which works out which control it is responding to from the sender parameter.
The latter, presented first here, is simpler for a one-off, but the former would be more re-usable, and you wouldn't have to maintain the list of Labels for the AddHandler.
Sub Label_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
Dim lbl = DirectCast(sender, Label)
If e.Button = MouseButtons.Right Then
If lbl.BorderStyle = BorderStyle.None Then
lbl.BorderStyle = BorderStyle.FixedSingle
Else
lbl.BorderStyle = BorderStyle.None
End If
End If
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
For Each l In {Label1, Label2}
AddHandler l.MouseDown, AddressOf Label_MouseDown
Next
End Sub
The AddHandler line connects the MouseDown event of each of the Labels to the specified event handler. (You can add more than one event handler to an event, if needed.)
For a control (your very own custom one) derived from an existing control (a System.Windows.Forms.Label in this case), let's call it BorderedControl, you can follow the instructions at How to: Inherit from Existing Windows Forms Controls (it's too close to plagiarism to copy it to here), and then your code for the control might look like:
Public Class BorderedLabel
Inherits Label
Protected Overrides Sub OnMouseDown(e As MouseEventArgs)
If e.Button = MouseButtons.Right Then
If Me.BorderStyle = BorderStyle.None Then
Me.BorderStyle = BorderStyle.FixedSingle
Else
Me.BorderStyle = BorderStyle.None
End If
End If
MyBase.OnMouseDown(e)
End Sub
Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
End Sub
End Class
After you have built your project after adding that code, you will find a new control, named "BorderedLabel", in the ToolBox. You can drag that onto the form "design surface" and it will behave just like an ordinary Label except that it will have your BorderStyle-changing code incorporated automatically.