c#3_16.xaml

<Style TargetType="Label">
        <Setter Property="Background" Value="LightGray"/>
        <Setter Property="FontSize" Value="20" />
        <Setter Property="VerticalContentAlignment" Value="Center" />
    </Style>

    <Style TargetType="Button" x:Key="CellStyle">

        <Setter Property="BorderThickness" Value="2"/>
        <Setter Property="BorderBrush" Value="DarkGray" />
        <Setter Property="FontSize" Value="65" />

        <Style.Triggers>
            <DataTrigger Binding="{Binding GameActive}" Value="True">
                <Setter Property="Background" Value="White"/>
                <Setter Property="IsEnabled" Value="True"/>
            </DataTrigger>
            <DataTrigger Binding="{Binding GameActive}" Value="False">
                <Setter Property="Background" Value="LightGray"/>
                <Setter Property="IsEnabled" Value="False"/>
                <Setter Property="Foreground" Value="Black"/>
            </DataTrigger>
        </Style.Triggers>
    </Style>



    <Style TargetType="Button" x:Key="ButtonStyle">
        <Setter Property="Background" Value="PaleGreen"/>
        <Setter Property="FontSize" Value="20" />
    </Style>

</Window.Resources>
<Grid>

    <Grid.RowDefinitions>
        <RowDefinition Height="50" />
        <RowDefinition Height="*" />
        <RowDefinition Height="50" />
    </Grid.RowDefinitions>

    <Label Grid.Row="0" Name="GameInformation"></Label>

    <Grid Grid.Row="1">

        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>

        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>

        <Button Click="Button_Click" Name="Button0_0" Grid.Column="0" Grid.Row="0" Style="{StaticResource CellStyle}" />
        <Button Click="Button_Click" Name="Button0_1" Grid.Column="0" Grid.Row="1" Style="{StaticResource CellStyle}" />
        <Button Click="Button_Click" Name="Button0_2" Grid.Column="0" Grid.Row="2" Style="{StaticResource CellStyle}" />

        <Button Click="Button_Click" Name="Button1_0" Grid.Column="1" Grid.Row="0" Style="{StaticResource CellStyle}" />
        <Button Click="Button_Click" Name="Button1_1" Grid.Column="1" Grid.Row="1" Style="{StaticResource CellStyle}" />
        <Button Click="Button_Click" Name="Button1_2" Grid.Column="1" Grid.Row="2" Style="{StaticResource CellStyle}" />

        <Button Click="Button_Click" Name="Button2_0" Grid.Column="2" Grid.Row="0" Style="{StaticResource CellStyle}" />
        <Button Click="Button_Click" Name="Button2_1" Grid.Column="2" Grid.Row="1" Style="{StaticResource CellStyle}" />
        <Button Click="Button_Click" Name="Button2_2" Grid.Column="2" Grid.Row="2" Style="{StaticResource CellStyle}" />
    </Grid>

    <Button Click="StartButton_Click" Name="StartButton" Grid.Row="2" Style="{StaticResource ButtonStyle}">Neues Spiel starten</Button>

</Grid>