WPF设置字体和字号

<Window x:Class="TestWpf.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:TestWpf"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" FontFamily="Microsoft YaHei" FontSize="15">

this.FontFamily = new FontFamily("Microsoft YaHei");
this.FontSize = 15;

<ComboBox Name="cmbFontFamily">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Source}" FontFamily="{Binding Source}" MouseDown="SelectFontFamily" />
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>

public MainWindow()
{
    InitializeComponent();

    //绑定字体数据源
    ICollection<FontFamily> fontList = Fonts.SystemFontFamilies;
    this.cmbFontFamily.ItemsSource = fontList.OrderBy(o => o.Source);
}

//选择字体
private void SelectFontFamily(object sender, MouseButtonEventArgs e)
{
    string wordStyle = ((TextBlock)sender).Text;
    this.FontFamily = new FontFamily(wordStyle);
}