Kapitel 7 abgeschlossen.

LehrerApp.Desktop/Views/Groups/GroupDetailView.axaml

@@ -7,7 +7,7 @@
              x:Class="LehrerApp.Desktop.Views.Groups.GroupDetailView"
              x:DataType="vm:GroupDetailViewModel">
 
-  <Grid RowDefinitions="Auto,*">
+  <Grid RowDefinitions="Auto,Auto,*">
 
     <!-- Header -->
     <Border Grid.Row="0" Padding="20,16"
@@ -22,18 +22,32 @@
           </TextBlock>
           <CheckBox Content="Ausgetretene anzeigen" IsChecked="{Binding ShowFormerStudents}"
                     VerticalAlignment="Center"/>
-          <Button Content="＋ Schüler"   Command="{Binding AddStudentCommand}"/>
+          <Button Content="＋ Schüler" Command="{Binding AddStudentCommand}" IsEnabled="{Binding IsEditable}"/>
           <Button Content="{Binding SelectedStudent.WithdrawActionLabel}"
                   Command="{Binding WithdrawStudentCommand}"
                   IsVisible="{Binding SelectedStudent, Converter={x:Static ObjectConverters.IsNotNull}}"/>
           <Button Content="Austragung zurücknehmen" Command="{Binding ReinstateStudentCommand}"
                   IsVisible="{Binding SelectedStudent.HasExitDate}"/>
-          <Button Content="＋ Klausur"   Command="{Binding AddExamCommand}"/>
+          <Button Content="＋ Klausur" Command="{Binding AddExamCommand}" IsEnabled="{Binding IsEditable}"/>
         </StackPanel>
       </Grid>
     </Border>
 
-    <TabbedPage Grid.Row="1" TabPlacement="Top" SelectedIndex="{Binding ActiveTabIndex}">
+    <Border Grid.Row="1" Background="#FFF3CD" BorderBrush="#D97706" BorderThickness="0,0,0,1"
+            Padding="20,10" IsVisible="{Binding IsReadOnly}">
+      <Grid ColumnDefinitions="*,Auto">
+        <StackPanel Grid.Column="0" Spacing="2">
+          <TextBlock Text="Archivierte Lerngruppe · schreibgeschützt" FontWeight="SemiBold"
+                     Foreground="#92400E"/>
+          <TextBlock Text="Alle historischen Daten bleiben sichtbar. Für Korrekturen muss die Gruppe ausdrücklich wieder aktiviert werden."
+                     FontSize="12" Foreground="#92400E" TextWrapping="Wrap"/>
+        </StackPanel>
+        <Button Grid.Column="1" Content="Gruppe wieder aktivieren"
+                Command="{Binding ReactivateGroupCommand}" Margin="16,0,0,0"/>
+      </Grid>
+    </Border>
+
+    <TabbedPage Grid.Row="2" TabPlacement="Top" SelectedIndex="{Binding ActiveTabIndex}">
 
       <!-- Tab: Übersicht -->
       <ContentPage Header="Übersicht">
@@ -57,6 +71,18 @@
                   CanUserResizeColumns="True"
                   Margin="0">
           <DataGrid.Columns>
+            <DataGridTemplateColumn Header="" Width="48">
+              <DataGridTemplateColumn.CellTemplate>
+                <DataTemplate x:DataType="vm:StudentSummary">
+                  <Border Width="30" Height="30" CornerRadius="15" Background="{Binding AvatarColor}"
+                          HorizontalAlignment="Center" VerticalAlignment="Center"
+                          ToolTip.Tip="{Binding AvatarTooltip}">
+                    <TextBlock Text="{Binding AvatarLabel}" Foreground="White" FontWeight="Bold"
+                               HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                  </Border>
+                </DataTemplate>
+              </DataGridTemplateColumn.CellTemplate>
+            </DataGridTemplateColumn>
             <DataGridTextColumn Header="Name"     Binding="{Binding FullName}"         Width="*"/>
             <DataGridTextColumn Header="Zeitraum" Binding="{Binding PeriodLabel}"      Width="190"/>
             <DataGridTextColumn Header="Status"   Binding="{Binding MembershipStatus}" Width="170"/>
@@ -66,6 +92,7 @@
                 <DataTemplate x:DataType="vm:StudentSummary">
                   <ComboBox ItemsSource="{x:Static vm:StudentSummary.NiveauOptions}"
                             SelectedItem="{Binding NiveauName}"
+                            IsEnabled="{Binding CanEdit}"
                             HorizontalAlignment="Stretch" Margin="2"/>
                 </DataTemplate>
               </DataGridTemplateColumn.CellTemplate>
@@ -83,7 +110,8 @@
       <ContentPage Header="Klausuren">
         <Grid RowDefinitions="Auto,*">
           <StackPanel Grid.Row="0" Orientation="Horizontal" Spacing="8" Margin="0,0,0,8"
-                      IsVisible="{Binding SelectedExam, Converter={x:Static ObjectConverters.IsNotNull}}">
+                      IsVisible="{Binding SelectedExam, Converter={x:Static ObjectConverters.IsNotNull}}"
+                      IsEnabled="{Binding IsEditable}">
             <Button Content="Punkte eingeben" Command="{Binding GradeExamCommand}"/>
             <Button Content="Auswertung"    Command="{Binding EvaluateExamCommand}"/>
             <Button Content="Bearbeiten"    Command="{Binding EditExamCommand}"/>