升级PDFsharp-MigraDoc后NewFontResolver未找到及Debian字体配置问题

一、修复NewFontResolver找不到的错误 #

NewFontResolver并非PDFsharp-MigraDoc的内置类型，你需要自定义实现IFontResolver接口来创建这个类，具体步骤如下：

1. 先引入必要的命名空间：

using PdfSharp.Fonts;
using System.IO;
using System.Collections.Generic;

2. 编写自定义的字体解析器类：

public class NewFontResolver : IFontResolver
{
    private readonly string _fontDirectory;

    public NewFontResolver(string fontDir)
    {
        _fontDirectory = fontDir;
    }

    // 匹配字体名称与对应样式的ttf文件
    public FontResolverInfo ResolveTypeface(string familyName, bool isBold, bool isItalic)
    {
        string fileName = familyName switch
        {
            "Times New Roman" when !isBold && !isItalic => "times.ttf",
            "Times New Roman" when isBold && !isItalic => "timesbd.ttf",
            "Times New Roman" when !isBold && isItalic => "timesi.ttf",
            "Times New Roman" when isBold && isItalic => "timesbi.ttf",
            "Arial" when !isBold && !isItalic => "arial.ttf",
            "Arial" when isBold && !isItalic => "arialbd.ttf",
            "Arial" when !isBold && isItalic => "ariali.ttf",
            "Arial" when isBold && isItalic => "arialbi.ttf",
            _ => null
        };

        return fileName == null ? null : new FontResolverInfo(familyName);
    }

    // 读取对应字体文件的字节内容
    public byte[] GetFont(string faceName)
    {
        string fileName = faceName switch
        {
            "Times New Roman" => "times.ttf",
            "Times New Roman Bold" => "timesbd.ttf",
            "Times New Roman Italic" => "timesi.ttf",
            "Times New Roman Bold Italic" => "timesbi.ttf",
            "Arial" => "arial.ttf",
            "Arial Bold" => "arialbd.ttf",
            "Arial Italic" => "ariali.ttf",
            "Arial Bold Italic" => "arialbi.ttf",
            _ => null
        };

        if (fileName == null) return null;

        string fullPath = Path.Combine(_fontDirectory, fileName);
        return File.ReadAllBytes(fullPath);
    }
}

3. 修改静态构造函数，传入Debian上的字体目录：

static ReportTemplateBase()
{
    string fontDir = "/usr/share/fonts/winfonts";
    GlobalFontSettings.FontResolver = new NewFontResolver(fontDir);
}

二、在Debian下使用指定目录的字体生成PDF #

1. 确保字体文件权限正常
   执行命令让程序能读取字体文件：

sudo chmod -R 644 /usr/share/fonts/winfonts
sudo chown -R root:root /usr/share/fonts/winfonts

2. 更新系统字体缓存（可选但推荐）
   让Debian识别新增的字体，避免系统层面的字体识别问题：

fc-cache -fv /usr/share/fonts/winfonts

3. 在PDF生成代码中直接调用字体
   编写PDF内容时，直接指定字体名称即可，示例：

var document = new MigraDoc.DocumentObjectModel.Document();
var section = document.AddSection();
var paragraph = section.AddParagraph("测试内容");
paragraph.Format.Font.Name = "Times New Roman";
paragraph.Format.Font.Size = 14;
paragraph.Format.Font.Bold = true;

内容的提问来源于stack exchange，提问作者Andrus