Neue Funktion Schüler austragen statt aus Kurs löschen.

LehrerApp.Desktop/Views/Groups/GradeOverviewTabView.axaml.cs

@@ -48,6 +48,7 @@ public partial class GradeOverviewTabView : UserControl
         var dialogVm = new CollectiveGradeDialogViewModel(
             App.Services.GetRequiredService<IGradeRepository>(),
             App.Services.GetRequiredService<IStudentRepository>(),
+            App.Services.GetRequiredService<IGroupMembershipRepository>(),
             _vm!.GroupId);
 
         var dialog = new CollectiveGradeDialog { DataContext = dialogVm };
@@ -66,7 +67,7 @@ public partial class GradeOverviewTabView : UserControl
             App.Services.GetRequiredService<IGradingSchemeRepository>(),
             App.Services.GetRequiredService<IReportGradeRepository>(),
             App.Services.GetRequiredService<GradingService>(),
-            _vm!.GroupId, _vm.GroupType, _vm.GradingSystem, _vm.GroupLabel);
+            _vm!.GroupId, _vm.GroupType, _vm.GradingSystem, _vm.GroupLabel, _vm.SchoolYear);
 
         var dialog = new ReportGradeDialog { DataContext = dialogVm };
         var owner = TopLevel.GetTopLevel(this) as Window;

LehrerApp.Desktop/Views/Groups/GroupDetailView.axaml

@@ -20,9 +20,14 @@
             <Run Text="{Binding StudentCount}"/>
             <Run Text=" Schüler"/>
           </TextBlock>
+          <CheckBox Content="Ausgetretene anzeigen" IsChecked="{Binding ShowFormerStudents}"
+                    VerticalAlignment="Center"/>
           <Button Content="＋ Schüler"   Command="{Binding AddStudentCommand}"/>
-          <Button Content="− Austragen"  Command="{Binding RemoveStudentCommand}"
+          <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}"/>
         </StackPanel>
       </Grid>
@@ -52,8 +57,9 @@
                   CanUserResizeColumns="True"
                   Margin="0">
           <DataGrid.Columns>
-            <DataGridTextColumn Header="Name"    Binding="{Binding FullName}"    Width="*"/>
-            <DataGridTextColumn Header="Zeitraum" Binding="{Binding PeriodLabel}" Width="90"/>
+            <DataGridTextColumn Header="Name"     Binding="{Binding FullName}"         Width="*"/>
+            <DataGridTextColumn Header="Zeitraum" Binding="{Binding PeriodLabel}"      Width="190"/>
+            <DataGridTextColumn Header="Status"   Binding="{Binding MembershipStatus}" Width="170"/>
             <DataGridTemplateColumn Header="Niveau" Width="130"
                                      IsVisible="{Binding IsDifferentiated}">
               <DataGridTemplateColumn.CellTemplate>

LehrerApp.Desktop/Views/Groups/GroupDetailView.axaml.cs

@@ -17,6 +17,7 @@ public partial class GroupDetailView : UserControl
         if (DataContext is GroupDetailViewModel vm)
         {
             vm.OnAddStudent      = ShowAddStudentDialog;
+            vm.OnWithdrawStudent = ShowWithdrawStudentDialog;
             vm.OnAddExam         = ShowAddExamDialog;
             vm.OnEditExam        = ShowEditExamDialog;
             vm.OnDuplicateExam   = ShowDuplicateExamDialog;
@@ -42,6 +43,20 @@ public partial class GroupDetailView : UserControl
         return await dialog.ShowDialog<bool>(owner);
     }
 
+    private async Task<bool> ShowWithdrawStudentDialog(StudentSummary student)
+    {
+        if (DataContext is not GroupDetailViewModel vm || vm.Group is null) return false;
+        var memberships = App.Services.GetRequiredService<IGroupMembershipRepository>();
+        var membership = memberships.GetByStudentAndGroup(student.Id, vm.Group.Id);
+        if (membership is null) return false;
+
+        var dialogVm = new WithdrawStudentDialogViewModel(
+            memberships, membership, student.FullName, vm.Group.Name);
+        var dialog = new WithdrawStudentDialog { DataContext = dialogVm };
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        return owner is not null && await dialog.ShowDialog<bool>(owner);
+    }
+
     private Task<bool> ShowAddExamDialog(Guid groupId) =>
         ShowExamDialog(groupId, editingExam: null, duplicateSource: null);
 

LehrerApp.Desktop/Views/Groups/ParticipationTabView.axaml.cs

@@ -290,6 +290,7 @@ public partial class ParticipationTabView : UserControl
             App.Services.GetRequiredService<IParticipationAspectRepository>(),
             App.Services.GetRequiredService<IParticipationSectionRepository>(),
             App.Services.GetRequiredService<IStudentRepository>(),
+            App.Services.GetRequiredService<IGroupMembershipRepository>(),
             App.Services.GetRequiredService<IExamRepository>(),
             App.Services.GetRequiredService<IExamResultRepository>(),
             App.Services.GetRequiredService<IGradeRepository>(),

LehrerApp.Desktop/Views/Groups/WithdrawStudentDialog.axaml

@@ -0,0 +1,42 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+        x:Class="LehrerApp.Desktop.Views.Groups.WithdrawStudentDialog"
+        x:DataType="vm:WithdrawStudentDialogViewModel"
+        Title="Schüler austragen"
+        Width="440" Height="330"
+        CanResize="False" WindowStartupLocation="CenterOwner">
+
+  <Grid RowDefinitions="*,Auto" Margin="24">
+    <StackPanel Grid.Row="0" Spacing="14">
+      <TextBlock Text="Schüler aus Lerngruppe austragen" Classes="dialogtitle"/>
+
+      <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
+              CornerRadius="6" Padding="12">
+        <Grid ColumnDefinitions="Auto,12,*" RowDefinitions="Auto,Auto">
+          <TextBlock Grid.Row="0" Grid.Column="0" Text="Schüler" Opacity="0.65"/>
+          <TextBlock Grid.Row="0" Grid.Column="2" Text="{Binding StudentName}" FontWeight="SemiBold"/>
+          <TextBlock Grid.Row="1" Grid.Column="0" Text="Lerngruppe" Opacity="0.65"/>
+          <TextBlock Grid.Row="1" Grid.Column="2" Text="{Binding GroupName}" FontWeight="SemiBold"/>
+        </Grid>
+      </Border>
+
+      <StackPanel Spacing="5">
+        <TextBlock Text="Austrittsdatum" FontSize="12" Opacity="0.7"/>
+        <CalendarDatePicker SelectedDate="{Binding SelectedDate}"
+                            DisplayDateStart="{Binding EarliestDate}"
+                            HorizontalAlignment="Stretch"/>
+        <TextBlock Text="{Binding DateError}" Foreground="Red" FontSize="12"
+                   IsVisible="{Binding DateError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+      </StackPanel>
+
+      <TextBlock Text="Die bisherige Gruppenzugehörigkeit und alle zugehörigen Leistungen bleiben erhalten."
+                 FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+    </StackPanel>
+
+    <Grid Grid.Row="1" ColumnDefinitions="*,8,*" Margin="0,18,0,0">
+      <Button Grid.Column="0" Content="Abbrechen" HorizontalAlignment="Stretch" Click="OnCancel"/>
+      <Button Grid.Column="2" Content="Austragen" HorizontalAlignment="Stretch" Click="OnSave"/>
+    </Grid>
+  </Grid>
+</Window>

LehrerApp.Desktop/Views/Groups/WithdrawStudentDialog.axaml.cs

@@ -0,0 +1,19 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using LehrerApp.Desktop.ViewModels.Groups;
+
+namespace LehrerApp.Desktop.Views.Groups;
+
+public partial class WithdrawStudentDialog : Window
+{
+    public WithdrawStudentDialog() => InitializeComponent();
+
+    private void OnSave(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not WithdrawStudentDialogViewModel vm) return;
+        vm.SaveCommand.Execute(null);
+        if (vm.WasSaved) Close(true);
+    }
+
+    private void OnCancel(object? sender, RoutedEventArgs e) => Close(false);
+}