Selecting 1 Tool Strip Menu Item at any one time - vb.net

Question

I have a Tool strip menu with 4 options.
The options are degrees of screen rotation. (0, 90, 180, 270)
I am trying to select only 1 of these and keep it selected.
When I choose one then another, both are ticked (selected).
I have searched and found some solutions but only this works for me.
I have used the click event for each option to clear the ones not chosen like below.
Private Sub DegreesToolStripMenuItem6_Click(sender As Object, e As EventArgs) Handles DegreesToolStripMenuItem6.Click
DegreesToolStripMenuItem6.Checked = True
DegreesToolStripMenuItem7.Checked = False
DegreesToolStripMenuItem8.Checked = False
DegreesToolStripMenuItem9.Checked = False
End Sub
This sub is in my code 4 times to make it work but i'm sure there must be a cleaner, easier way to do this.
I have found online some other solutions but I can't seem to make it work, this one kind of makes sense like it should work but I can't figure it out
Private Sub DegreesToolStripMenuItem6_CheckedChanged(sender As Object, e As EventArgs) Handles DegreesToolStripMenuItem6.CheckedChanged, _
DegreesToolStripMenuItem7.CheckedChanged, _
DegreesToolStripMenuItem8.CheckedChanged, _
DegreesToolStripMenuItem9.CheckedChanged
Dim currentItem As ToolStripMenuItem = TryCast(sender, ToolStripMenuItem)
If currentItem IsNot Nothing AndAlso currentItem.Checked Then
Dim menu As ContextMenuStrip = TryCast(currentItem.Owner, ContextMenuStrip)
If menu IsNot Nothing Then
'The current item has just been checked so uncheck all other items on the same context menu strip.
For Each item As ToolStripMenuItem In menu.Items
If item IsNot currentItem Then
item.Checked = False
End If
Next item
End If
End If
End Sub
the toolstrip menu reads like this
-PreferedRotationToolStripMenuItem-DegreesToolStripMenuItem6
DegreesToolStripMenuItem7
DegreesToolStripMenuItem8
DegreesToolStripMenuItem9
Thanks for your time and looking forward to any help you guys can give.

Answer 1

Set CheckOnClick to True for each menu item, which I'm guessing you already have. This code worked for me:
Private Sub ToolStripMenuItems_CheckedChanged(sender As Object, e As EventArgs) Handles DegreesToolStripMenuItem9.CheckedChanged,
DegreesToolStripMenuItem8.CheckedChanged,
DegreesToolStripMenuItem7.CheckedChanged,
DegreesToolStripMenuItem6.CheckedChanged
Dim currentMenuItem = DirectCast(sender, ToolStripMenuItem)
If currentMenuItem.Checked Then
Dim menu = DirectCast(currentMenuItem.Owner, ContextMenuStrip)
For Each menuItem In menu.items.Cast(Of ToolStripMenuItem)
menuItem.Checked = menuItem Is currentMenuItem
Next
End If
End Sub
Here's a slight variation that avoids checking the already checked current item:
Private Sub ToolStripMenuItems_CheckedChanged(sender As Object, e As EventArgs) Handles DegreesToolStripMenuItem9.CheckedChanged,
DegreesToolStripMenuItem8.CheckedChanged,
DegreesToolStripMenuItem7.CheckedChanged,
DegreesToolStripMenuItem6.CheckedChanged
Dim currentMenuItem = DirectCast(sender, ToolStripMenuItem)
If currentMenuItem.Checked Then
Dim menu = DirectCast(currentMenuItem.Owner, ContextMenuStrip)
For Each menuItem In menu.Items.Cast(Of ToolStripMenuItem).Except({currentMenuItem})
menuItem.Checked = False
Next
End If
End Sub
The code above works if you have added the items to a ContextMenuStrip. If you have added them directly to an item on a MenuStrip then change this:
Dim menu = DirectCast(currentMenuItem.Owner, ContextMenuStrip)
to this:
Dim menu = DirectCast(currentMenuItem.Owner, ToolStripDropDownMenu)