Public Class frmMessage
 
    Dim _messagetext As String
 
    Public Property MessageText As String
        Set(value As String)
            _messagetext = value
        End Set
        Get
            Return _messagetext
        End Get
    End Property
 
    Private _messagefont As Font
 
    Public Property Messagefont As Font
        Set(value As Font)
            _messagefont = value
        End Set
        Get
            Return _messagefont
        End Get
    End Property
 
 
    Public ReadOnly Property GetGraphics As Drawing.Graphics
        Get
            Return lblMessage.CreateGraphics
        End Get
    End Property
 
 
    Dim WithEvents lblMessage As New Label With {.Parent = Me}
 
 
    Private Sub frmMessage_Load(sender As Object, 
        e As EventArgs) Handles MyBase.Load
 
        Me.FormBorderStyle = FormBorderStyle.None
 
        'Me.TransparencyKey = Color.Transparent
 
        lblMessage.BackColor = Color.White
 
        With lblMessage.DataBindings
            .Add("Text", Me, "Messagetext")
            .Add("Font", Me, "Messagefont")
        End With
 
    End Sub
 
 
    Private Sub frmMessage_Resize(sender As Object, 
        e As EventArgs) Handles Me.Resize
 
        lblMessage.Size = 
        New Drawing.Size(Me.ClientRectangle.Width, Me.ClientRectangle.Height)
    End Sub
 
 
    Private Sub lblMessage_Click(sender As Object, 
        e As EventArgs) Handles lblMessage.Click
 
        Me.Close()
    End Sub
End Class

Public Class frmMother
 
 
    Dim pl As New Panel With _
        {.Parent = Me, .BorderStyle = BorderStyle.Fixed3D}
 
    Dim WithEvents btnMessage As New Button With
        {.Parent = pl, .Location = New Point(100, 100),
        .Text = "Show Message", .Width = 100}
 
 
    Private Sub frmMother_Load(sender As Object, 
        e As EventArgs) Handles MyBase.Load
 
        Me.Size = New Size(500, 500)
    End Sub
 
 
    Private Sub btnMessage_Click(sender As Object, 
        e As EventArgs) Handles btnMessage.Click
 
        Me.Opacity = 0.5 'Hauptformular teil-transparent anzeigen
 
        Using Mymessage As New frmMessage
            With Mymessage
                'Eigentümer des Dialogs setzen
                .Owner = Me
 
                'Text und Font der Meldung 
                .MessageText =
                    "Das ist eine Meldung. " &
                    "Bei einem Click auf das Meldefenster " & 
                    "wird die Anzeige beendet."
 
                .Messagefont = New Font("Arial", 16, FontStyle.Italic)
 
                'Erforderliche Höhe der Meldung 
                'bei festgelegter Breite ermitteln
                Dim sz As SizeF
                Dim message_width As Integer = 200
                Using g As Graphics = .GetGraphics
                    sz = g.MeasureString(.MessageText, .Messagefont, 
                                         message_width)
                End Using
                .ClientSize = New Size(message_width, CInt(sz.Height * 1.1))
 
                'Dialog lokalisieren und ausführen
                .StartPosition = FormStartPosition.CenterParent
                .ShowDialog()
            End With
        End Using
 
        Me.Opacity = 1 'Hauptformular ohne Transparenz
    End Sub
 
 
    Private Sub frmMother_Resize(sender As Object, 
        e As EventArgs) Handles Me.Resize
 
        pl.Size = Me.ClientSize
    End Sub
End Class