Sevral bugfixes

BuechermarktClient/Students.xaml

@@ -31,6 +31,7 @@
                     <GridViewColumn Header="Telefon" DisplayMemberBinding="{Binding PhoneNumber}" Width="Auto"></GridViewColumn>
                     <GridViewColumn Header="LabelId" DisplayMemberBinding="{Binding LabelId}" Width="Auto"></GridViewColumn>
                     <GridViewColumn Header="Klasse" DisplayMemberBinding="{Binding Form}" Width="Auto"></GridViewColumn>
+                    <GridViewColumn Header="ID" DisplayMemberBinding="{Binding ID}" Width="Auto"></GridViewColumn>
                 </GridView>
             </ListView.View>
             <ListView.ItemContainerStyle>

BuechermarktClient/StudentsEdit.xaml

@@ -5,7 +5,7 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:BuechermarktClient"
         mc:Ignorable="d"
-        Title="Schüler" Height="335" Width="300">
+        Title="Schüler" Height="393.494" Width="300">
     <StackPanel VerticalAlignment="Top">
         <Label Content="Vorname" Margin="10,0"></Label>
         <TextBox Margin="10,0" Text="{Binding Path=Forname, Mode=TwoWay}"></TextBox>
@@ -19,6 +19,8 @@
         <TextBox Margin="10,0" Text="{Binding Path=LabelId, Mode=TwoWay}"></TextBox>
         <Label Content="Klasse" Margin="10,0"></Label>
         <TextBox Margin="10,0" Text="{Binding Path=Form, Mode=TwoWay}"></TextBox>
+        <Label Content="iD" Margin="10,0"></Label>
+        <TextBox Margin="10,0" Text="{Binding Path=ID, Mode=OneWay}"></TextBox>
         <Grid Margin="10,10,10,0">
             <Grid.ColumnDefinitions>
                 <ColumnDefinition Width="*"></ColumnDefinition>

BuechermarktClient/StudentsEdit.xaml.cs

@@ -77,6 +77,14 @@ namespace BuechermarktClient
          }
       }
 
+      public string ID
+      {
+         get
+         {
+            return Student.ID.ToString();
+         }
+      }
+
       public string LabelId
       {
          get