WPF字体大小随着控件大小自动变化

参考文章：https://blog.csdn.net/ljz_1985/article/details/17141087
实现的效果如下所示：（不使用ViewBox）当窗体变大或者缩小时，计算字体大小，然后绑定

前台代码如下：
MainWindow.xaml:

<Window x:Class="WPF自动调整FontSize.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:WPF自动调整FontSize"
        mc:Ignorable="d"
        Title="MainWindow" Height="100" WindowStartupLocation="CenterScreen" SizeChanged="Window_SizeChanged" Width="100" d:DataContext="{d:DesignInstance local:MainWindowViewModel}">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <Grid x:Name="gridRow0">
            <TextBlock HorizontalAlignment="Center" Text="{Binding Text1}" FontSize="{Binding Text1FontSize}" VerticalAlignment="Center">Hello World</TextBlock>
            <TextBlock Text="{Binding Text1FontSize}" HorizontalAlignment="Right" VerticalAlignment="Bottom"></TextBlock>
        </Grid>
        <Grid x:Name="gridRow1"  Grid.Row="1">
            <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="{Binding Text2FontSize}" Text="{Binding Text2}">WPF</TextBlock>
            <TextBlock Text="{Binding Text2FontSize}" HorizontalAlignment="Right" VerticalAlignment="Bottom"></TextBlock>
        </Grid>
    </Grid>
</Window>

MainWindow.xaml.cs:

namespace WPF自动调整FontSize
{
    /// 

    /// MainWindow.xaml 的交互逻辑
    /// 
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = new MainWindowViewModel(this);
        }

        private void Window_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            (this.DataContext as MainWindowViewModel)?.RaiseSizeChanged();
        }
    }
}

MainWindowViewModel.cs:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Media;

namespace WPF自动调整FontSize
{
    public class MainWindowViewModel : INotifyPropertyChanged
    {
        private MainWindow _view;
        public MainWindowViewModel(MainWindow view)
        {
            this._view = view;
        }
        /// 

        /// Measures the size of the text.
        /// 
        /// The text.
        /// The font family.
        /// The font style.
        /// The font weight.
        /// The font stretch.
        /// Size of the font.
        /// 
        private static Size MeasureTextSize(
            string text, FontFamily fontFamily,
            FontStyle fontStyle,
            FontWeight fontWeight,
            FontStretch fontStretch,
            double fontSize)
        {
            FormattedText ft = new FormattedText(text,
                                                 CultureInfo.CurrentCulture,
                                                 System.Windows.FlowDirection.LeftToRight,
                                                 new Typeface(fontFamily, fontStyle, fontWeight, fontStretch),
                                                 fontSize,
                                                 Brushes.Black);
            return new Size(ft.Width, ft.Height);
        }


        /// 

        /// Get the required height and width of the specified text. Uses Glyph's
        /// 
        private static Size MeasureText(string text, FontFamily fontFamily,
            FontStyle fontStyle, FontWeight fontWeight,
            FontStretch fontStretch, double fontSize)
        {
            Typeface typeface = new Typeface(fontFamily, fontStyle, fontWeight, fontStretch);
            GlyphTypeface glyphTypeface;


            if (!typeface.TryGetGlyphTypeface(out glyphTypeface))
            {
                return MeasureTextSize(text, fontFamily, fontStyle, fontWeight, fontStretch, fontSize);
            }


            double totalWidth = 0;
            double height = 0;


            for (int n = 0; n < text.Length; n++)
            {
                ushort glyphIndex = glyphTypeface.CharacterToGlyphMap[text[n]];


                double width = glyphTypeface.AdvanceWidths[glyphIndex] * fontSize;


                double glyphHeight = glyphTypeface.AdvanceHeights[glyphIndex] * fontSize;


                if (glyphHeight > height)
                {
                    height = glyphHeight;
                }


                totalWidth += width;
            }


            return new Size(totalWidth, height);
        }

        private static int minFontSize = 1;
        private static int maxFontSize = 500;
        /// 

        /// Limits the size of the control font.
        /// 
        /// The text.
        /// The font family.
        /// The font style.
        /// The font weight.
        /// The font stretch.
        private double GetFontSize(
            string text,
            FontFamily fontFamily,
            FontStyle fontStyle,
            FontWeight fontWeight,
            FontStretch fontStretch,
            double width, double height)
        {
            for (int i = minFontSize; i <= maxFontSize; i++)
            {
                Size size = MeasureText(text, fontFamily, fontStyle,
                   fontWeight, fontStretch, i);
                if (width - 20 <= size.Width ||
                    height - 10 <= size.Height)
                {
                    return i;
                }
            }
            return maxFontSize;
        }
        private string text1 = "Hello World";
        public string Text1
        {
            get { return text1; }
            set { text1 = value; this.RaisePropertyChanged(nameof(Text1)); }
        }
        private string text2 = "WPF";
        public string Text2
        {
            get { return text2; }
            set { text2 = value; this.RaisePropertyChanged(nameof(Text2)); }
        }
        public double Text1FontSize
        {
            get { return GetFontSize(this.Text1, this._view.FontFamily, this._view.FontStyle, this._view.FontWeight, this._view.FontStretch, this._view.gridRow0.ActualWidth, this._view.gridRow0.ActualHeight); }
        }
        public double Text2FontSize
        {
            get { return GetFontSize(this.Text2, this._view.FontFamily, this._view.FontStyle, this._view.FontWeight, this._view.FontStretch, this._view.gridRow1.ActualWidth, this._view.gridRow1.ActualHeight); }
        }
        public event PropertyChangedEventHandler PropertyChanged;
        private void RaisePropertyChanged(string name)
        {
            this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
        }
        internal void RaiseSizeChanged()
        {
            this.RaisePropertyChanged(nameof(Text1FontSize));
            this.RaisePropertyChanged(nameof(Text2FontSize));
        }
    }
}