Public Class LoginForm1
 
    'Dieses Form vergleicht die eingegebenen Userinformationen
    'mit der Datenbank und überprüft, welche Rechte dem User
    'zugewiesen werden
 
    'Hier werden die globalen Variablen für die Connection angegeben
    Private con As New OleDb.OleDbConnection
    Private strCon As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & "Data" & _
      "Source=C:\Freibage\WatchGuard.mdb;" & "Jet OLEDB:database Password=xy;"
 
    Private Sub OK_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles OK.Click
        'Wird der Button "Okay" betätigt,
        'wird die Routine LoginForm1 versteckt und
        'daraufhin die Routine Form1 aufgerufen
        UsernameTextBox.Copy()
        TextBoxUser.Paste()
        PasswordTextBox.Copy()
        TextBoxPW.Paste()
    End Sub
 
    Private Sub Cancel_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Cancel.Click
        'Wird der Button "Cancel" betätigt,
        'wird das Programm beendet
        Form1.Close()
        ConForm.Close()
        Me.Close()
    End Sub
 
    Private Sub LogoPictureBox_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles LogoPictureBox.Click
        'Zeigt das Bild links neben dem Login an
 
    End Sub
 
    Private Sub LoginForm1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load, OK.Enter
 
    End Sub
 
    Private Sub TextBoxPW_TextChanged(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles TextBoxPW.TextChanged
        Try
            Dim DSPW As New DataSet
 
            con.ConnectionString = strCon
 
            Dim oledbadapter As OleDb.OleDbDataAdapter
 
            oledbadapter = New OleDb.OleDbDataAdapter("SELECT Passwort FROM" & _
              "Benutzer", con)
 
            con.Open()
 
            oledbadapter.Fill(DSPW, "PW")
 
            If PasswordTextBox.Text = DSPW.Tables("PW").Rows(0)( _
              "Passwort").ToString() Then
                oledbadapter.Dispose()
                PasswordTextBox.Clear()
                Me.Hide()
                Form1.Show()
            Else
                MessageBox.Show("Falsches Passwort!")
            End If
 
        Catch ex As Exception
            MessageBox.Show(Me, "Fehler aufgetreten : " + ex.ToString)
        Finally
            If con IsNot Nothing Then
                con.Close()
            End If
        End Try
    End Sub
 
    Private Sub TextBoxUser_TextChanged(ByVal sender As System.Object, ByVal e _
      As System.EventArgs) Handles TextBoxUser.TextChanged
        Try
            Dim DSUser As New DataSet
 
            con.ConnectionString = strCon
 
            Dim oledbadapter As OleDb.OleDbDataAdapter
 
            oledbadapter = New OleDb.OleDbDataAdapter("SELECT User FROM" & _
              "Benutzer", con)
 
            con.Open()
 
            oledbadapter.Fill(DSUser, "Usr")
 
            If UsernameTextBox.Text = DSUser.Tables("Usr").Rows(0)( _
              "User").ToString() Then
                oledbadapter.Dispose()
                UsernameTextBox.Clear()
            Else
                MessageBox.Show("Falscher Benutzername!")
            End If
 
        Catch ex As Exception
            MessageBox.Show(Me, "Fehler aufgetreten : " + ex.ToString)
        Finally
            If con IsNot Nothing Then
                con.Close()
            End If
        End Try
    End Sub
End Class