WPF Learn： Resouse

<Window.Resources>
        <Style x:Key="buttonStyle" TargetType="Button">
            <Setter Property="Background" Value="White"></Setter>
            <Style.Triggers>
                <Trigger Property="Button.IsMouseOver" Value="True">
                    <Setter Property="Foreground" Value="Blue"></Setter>
                </Trigger>
                <Trigger Property="Button.IsMouseOver" Value="False">
                    <Setter Property="Foreground" Value="Black"></Setter>
                </Trigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <Grid>
        <Button Content="Button" Height="23" HorizontalAlignment="Left" Style="{StaticResource ResourceKey=buttonStyle}"  Margin="64,87,0,0" Name="button1" VerticalAlignment="Top" Width="75" />
        <Button Content="Button" Height="23" HorizontalAlignment="Left"  Style="{StaticResource ResourceKey=buttonStyle}" Margin="64,136,0,0" Name="button2" VerticalAlignment="Top" Width="75" />
        <Button Content="Button" Height="23" HorizontalAlignment="Left"  Style="{StaticResource ResourceKey=buttonStyle}" Margin="68,187,0,0" Name="button3" VerticalAlignment="Top" Width="75" />
    </Grid>