Avalonia 在银河麒麟系统系统字体图标加载异常问题处理

刘恋

using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Runtime.InteropServices;
using Avalonia.Media;
using Avalonia.Media.Fonts;
using Avalonia.Platform;
using Avalonia.Skia;
using SkiaSharp;

namespace LinuxShelfUI
{
    public class CustomFontManagerImpl : IFontManagerImpl
    {
        private readonly Typeface[] _customTypefaces;
        private readonly string _defaultFamilyName;

        //Load font resources in the project, you can load multiple font resources
        private readonly Typeface _defaultTypeface =new Typeface("resm:AvaloniaDemo.Assets.Fonts.msyh#微软雅黑");
 
        private readonly Typeface _emojiTypeface = new Typeface("resm:AvaloniaDemo.Assets.Fonts.FluentAvalonia#Symbols");

        public CustomFontManagerImpl()
        {
            _customTypefaces = new[] { _defaultTypeface, _emojiTypeface };
            _defaultFamilyName = _defaultTypeface.FontFamily.FamilyNames.PrimaryFamilyName;
        }

        public string GetDefaultFontFamilyName()
        {
            return _defaultFamilyName;
        }

        public IEnumerable<string> GetInstalledFontFamilyNames(bool checkForUpdates = false)
        {
            return _customTypefaces.Select(x => x.FontFamily.Name);
        }

        private readonly string[] _bcp47 = { CultureInfo.CurrentCulture.ThreeLetterISOLanguageName, CultureInfo.CurrentCulture.TwoLetterISOLanguageName };

        public bool TryMatchCharacter(int codepoint, FontStyle fontStyle, FontWeight fontWeight, FontFamily fontFamily,
            CultureInfo culture, out Typeface typeface)
        {
            foreach (var customTypeface in _customTypefaces)
            {
                if (customTypeface.GlyphTypeface.GetGlyph((uint)codepoint) == 0)
                {
                    continue;
                }

                typeface = new Typeface(customTypeface.FontFamily.Name, fontStyle, fontWeight);

                return true;
            }

            var fallback = SKFontManager.Default.MatchCharacter(fontFamily?.Name, (SKFontStyleWeight)fontWeight,
                SKFontStyleWidth.Normal, (SKFontStyleSlant)fontStyle, _bcp47, codepoint);

            typeface = new Typeface(fallback?.FamilyName ?? _defaultFamilyName, fontStyle, fontWeight);

            return true;
        }

        public IGlyphTypefaceImpl CreateGlyphTypeface(Typeface typeface)
        {
            SKTypeface skTypeface;

            switch (typeface.FontFamily.Name)
            {
               
                case FontFamily.DefaultFontFamilyName:
                case "微软雅黑":  //font family name
                    skTypeface = SKTypeface.FromFamilyName(_defaultTypeface.FontFamily.Name); break;
                case "Symbols": //解决Linux系统加载不了字体图标的异常
                    skTypeface = SKTypeface.FromFamilyName(_emojiTypeface.FontFamily.Name); break;
                default:
                    skTypeface = SKTypeface.FromFamilyName(typeface.FontFamily.Name,
                        (SKFontStyleWeight)typeface.Weight, SKFontStyleWidth.Normal, (SKFontStyleSlant)typeface.Style);
                    break;
            }

            //解决linux系统下skTypeface是null
            if (skTypeface == null)
            {
                skTypeface = SKTypeface.FromFamilyName(_defaultTypeface.FontFamily.Name);
            }

            //如果是centos7之类的使用linux里面的字体
            if (skTypeface == null)
            {
                skTypeface = SKTypeface.FromFamilyName("WenQuanYi Micro Hei");
            }

            return new GlyphTypefaceImpl(skTypeface);
        }
    }
}

 S:参考标红部分代码

来源：https://www.cnblogs.com/-wxh/p/15984071.html