Public Class LoginLogout
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles btnLogin.Click
        login()
    End Sub
 
    Private Sub login()
 
        If txbUserName.TextLength <= 0 Then
            MsgBox("Sie müssen einen Benutzernamen eingeben.", CType( _
              MsgBoxStyle.Information + MsgBoxStyle.OkCancel, MsgBoxStyle))
            Exit Sub
        ElseIf txbUserPassword.TextLength <= 0 Then
            MsgBox("Sie müssen ein Passwort eingeben.", CType( _
              MsgBoxStyle.Information + MsgBoxStyle.OkCancel, MsgBoxStyle))
            Exit Sub
        End If
 
        Dim connection As New MySqlClient.MySqlConnection
        Dim connectionString As String = _
          "server=xxxx;user=xxxx;password=xxxx;database=xxxx;"
        Dim query As New MySqlClient.MySqlCommand
        Dim adapter As New MySqlDataAdapter
        Dim reader As MySqlClient.MySqlDataReader
 
        Try
            With query
                .Connection = connection
                .Connection.ConnectionString = connectionString
                .Connection.Open()
                .CommandText = "SELECT uid, password FROM user WHERE username =" & _
                  "?username AND password = md5(?password) LIMIT 1"
                .Parameters.AddWithValue("?username", txbUserName.Text)
                .Parameters.AddWithValue("?password", txbUserPassword.Text)
            End With
 
            adapter.SelectCommand = query
            reader = query.ExecuteReader()
            reader.Read()
 
            'Prüfroutine
            If reader.HasRows = False Then
                MsgBox("Zugangsdaten sind falsch.", CType( _
                  MsgBoxStyle.Information + MsgBoxStyle.OkCancel, MsgBoxStyle))
                Exit Sub
            Else
                MsgBox("Herzlichen Glückwunsch. Du hast dich erfolgreich" & _
                  "angemeldet.", CType(MsgBoxStyle.Information + _
                  MsgBoxStyle.OkCancel, MsgBoxStyle))
                Me.Close()
            End If
            '----------------------------
 
            reader.Close()
        Catch ex As Exception
            MsgBox(ex.ToString)
        Finally
            query.Connection.Close()
        End Try
 
    End Sub
 
    Private Sub logout()
 
    End Sub
End Class

-------------------------------
LG
f34rless


Visual Studio 2008 Proffesional
-------------------------------