update

Test_App/App.xaml

@@ -8,6 +8,7 @@
             <ResourceDictionary.MergedDictionaries>
                 <ResourceDictionary Source="Style/Menu_Button_Style.xaml"/>
                 <ResourceDictionary Source="Style/Textbox_Style.xaml"/>
+                <ResourceDictionary Source="Style/Custom_window.xaml"/>
             </ResourceDictionary.MergedDictionaries>
         </ResourceDictionary>
     </Application.Resources>

Test_App/Style/Custom_window.xaml

@@ -0,0 +1,17 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <Style BasedOn="{StaticResource {x:Type TextBox}}"
+           TargetType="{x:Type TextBox}"
+           x:Key="Custom_Window">
+        <Setter Property="Background" Value="#232041"/>
+        <Setter Property="FontSize" Value="22"/>
+        <Setter Property="FontFamily" Value="Tw Cen MT"/>
+        <Setter Property="Foreground" Value="White"/>
+        <Setter Property="Width" Value="430"/>
+        <Setter Property="VerticalAlignment" Value="Stretch"/>
+        <Setter Property="TextWrapping" Value="Wrap"/>
+        <Setter Property="TextWrapping" Value="Wrap"/>
+        <Setter Property="TextAlignment" Value="Center"/>
+
+    </Style>
+</ResourceDictionary>

Test_App/Test_App.csproj

@@ -86,6 +86,10 @@
       <DependentUpon>MainWindow.xaml</DependentUpon>
       <SubType>Code</SubType>
     </Compile>
+    <Page Include="Style\Custom_window.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="Style\Textbox_Style.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -138,7 +142,6 @@
       <Generator>SettingsSingleFileGenerator</Generator>
       <LastGenOutput>Settings.Designer.cs</LastGenOutput>
     </None>
-    <None Include="Ressources\Students.json" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />

Test_App/Views/Database.xaml

@@ -7,9 +7,9 @@
       mc:Ignorable="d" 
       d:DesignHeight="525" d:DesignWidth="602">
     <Page.Resources>
-        <DataTemplate x:Key="datas">
+        <DataTemplate x:Key="datas" >
             <Border Name="border" BorderBrush="DarkSlateBlue" BorderThickness="2"  
-      CornerRadius="2" Padding="5" Margin="5" Background="WhiteSmoke">
+                Padding="5" Margin="5" Background="WhiteSmoke" Width="700" MouseEnter="border_MouseEnter" MouseLeave="border_MouseLeave" CornerRadius="10,10,10,10">
                 <Grid>
                     <Grid.RowDefinitions>
                         <RowDefinition Height="*"/>
@@ -27,7 +27,7 @@
                     <TextBlock Grid.Row="1" Grid.Column="0" Padding="0,0,5,0" Text="Question: "/>
                     <TextBlock Grid.Row="1" Grid.Column="1" Text="{Binding Path=Question}"/>
                     <TextBlock Grid.Row="2" Grid.Column="0" Padding="0,0,5,0" Text="Answer:"/>
-                    <TextBlock Grid.Row="2" Grid.Column="1" Text="{Binding Path=Answer}"/>
+                    <TextBlock Name="answer_id" Grid.Row="2" Grid.Column="1" Text="{Binding Path=Answer}"/>
                    
                 </Grid>
             </Border>
@@ -35,12 +35,12 @@
     </Page.Resources>
 
     <DockPanel>
-        <Label DockPanel.Dock="Top" FontSize="20" Margin="5" Content="Database"/>
         <ListBox x:Name="datalist"
+            Background="#232041"
             ItemsSource="{Binding}"
             ItemTemplate="{StaticResource datas}"
             HorizontalAlignment="Stretch"
             IsSynchronizedWithCurrentItem="True"
-            Margin="5,0,5,5" />
+            Margin="5,0,5,5" Width="750" MouseDoubleClick="itemOnClick"/>
     </DockPanel>
 </Page>

Test_App/Views/Database.xaml.cs

@@ -47,7 +47,35 @@ namespace Test_App.Views
             datalist.ItemsSource = Newtonsoft.Json.JsonConvert.DeserializeObject<List<Ressources.Datas>>(json);
         }
 
+        private void border_MouseEnter(object sender, MouseEventArgs e)
+        {
+            Border border = sender as Border;
+            border.Background = new SolidColorBrush(Colors.LightGray);
+        }
+
+        private void border_MouseLeave(object sender, MouseEventArgs e)
+        {
+            Border border = sender as Border;
+            border.Background = new SolidColorBrush(Colors.WhiteSmoke);
+        }
+
+        private void itemOnClick(object sender, MouseButtonEventArgs e)
+        {
+            Ressources.Datas current = datalist.SelectedItem as Ressources.Datas;
+
+            TextBox textBox = new TextBox();
+            textBox.Style = (Style)FindResource("Custom_Window");
+            textBox.Text = "Antwort: \n" + current.Answer + "\n";
+
+            Window window = new Window();
+            window.Width = 550;
+            window.Height = 300;
+            window.SizeToContent = SizeToContent.WidthAndHeight;
+            window.Content = textBox;
+            window.Show();
+        }
     }
 }
 
 
+