Binding UserControl to ViewModel (Caliburn Micro WPF) - wpf

Question

I am creating a login form that will be used by many different applications. The login will always have the same logic, so I'd like to bind a viewmodel and do all logic there (Retrieving login info from database, etc). I created a new UserControl, MainView and a ViewModel, MainViewModel both of which are in a Login namespace.
The form continues to run everything in the code-behind, but nothing in the VM.
Is there another way of binding that I am not aware of?
Code-Behind MainView.Xaml.vb
Imports Caliburn.Micro
Namespace Login
Public Class MainView
Public Sub New()
MsgBox("TEST code-behind")
End Sub
End Class
End Namespace
VM MainViewModel.vb
Imports Caliburn.Micro
Namespace Login
Public Class MainViewModel
Inherits PropertyChangedBase
Public Sub New()
MsgBox("TEST ViewModel")
End Sub
End Class
End Namespace
Xaml
<UserControl x:Class="Login.MainView"
xmlns:cal="http://www.caliburnproject.org"
xmlns:local="clr-namespace:cLogin.Login"
cal:Bind.Model="cLogin.Login.MainViewModel" (not sure if needed due to naming)
... >
EDIT
This is how I have added the UserControl as a separate window before the user is logged in, I can see the content, but none of the properties inside the ViewModel bind
Dim login As New Window
With login
.WindowStyle = WindowStyle.None
.ResizeMode = ResizeMode.NoResize
.SizeToContent = SizeToContent.WidthAndHeight
.Content = New MainView()
End With
login.ShowDialog()

Answer 1

Since you are creating the window explicitly, you also need to explicitly set its DataContext:
Dim login As New Window
With login
.WindowStyle = WindowStyle.None
.ResizeMode = ResizeMode.NoResize
.SizeToContent = SizeToContent.WidthAndHeight
.Content = New MainView()
.DataContext = New MainViewModel()
End With
You should also bind the attached Bind.Model property to the DataContext in the view:
cal:Bind.Model="{Binding}"