Public Class frmWerkTage2
 
    'Labels
    Dim lblStart As New Label With _
        {.Parent = Me, .Width = 200, .Text = "Projekteingang: "}
 
    Dim WithEvents dtpStart As New DateTimePicker With _
        {.Parent = Me, .Top = 40, _
        .Width = 200, .Value = CDate(Now)}
 
    Dim lblDauer As New Label With _
        {.Parent = Me, .Width = 100, .Left = 250, .Top = 40, _
         .Text = "Projekt-Dauer: "}
 
    Dim WithEvents txtDauer As New TextBox With _
        {.Parent = Me, .Width = 100, .Left = 350, .Top = 40, _
        .Text = "3"}
 
    'Berechnungsbutton
    Dim WithEvents btnCompute As New Button With _
        {.Parent = Me, .Top = 100, _
        .Width = 200, .Text = "Berechne Datum Projektende"}
 
    'Anzeige des Ergebnisses
    Dim lblWerktage As New Label With _
        {.Parent = Me, .Top = 100, .Left = 250, _
        .Width = 200, .Text = "", .BackColor = Color.LightGray}
 
    Private Sub btnCompute_Click(ByVal sender As Object, _
            ByVal e As System.EventArgs) Handles btnCompute.Click
 
        Dim dt As Date = DateValue(dtpStart.Value.ToString)
        Dim dauer As Integer
        If Not Integer.TryParse(txtDauer.Text, dauer) OrElse dauer < 1 Then
            MsgBox("Fehlerhafte Angabe zur Projektdauer (mind. 1 Tag)")
        End If
 
        Dim c As Integer
        Do
            Dim wochentag As Integer = Microsoft.VisualBasic.Weekday(dt)
            'Unter Annahme: 1 = Sonntag, 7 = Samstag
            If wochentag > 1 And wochentag < 7 Then
                c += 1
            End If
            dt = dt.AddDays(1)
        Loop While c < dauer
 
        'Annahme: Datum letzter Projekttag = Datum Projektende
        lblWerktage.Text = "Projektende: " & CStr(dt.AddDays(-1))
    End Sub
 
    Private Sub dtp_ValueChanged(ByVal sender As Object, ByVal e As  _
      System.EventArgs) _
        Handles dtpStart.ValueChanged, txtDauer.TextChanged
        lblWerktage.Text = ""
    End Sub
 
    Private Sub frmWerkTage2_Load(sender As System.Object, _
        e As System.EventArgs) Handles MyBase.Load
        Me.Width = 600
    End Sub
End Class