MemoryFontSource

public MemoryFontSource(byte[] fontData)

byte[] fontBytes = File.ReadAllBytes(MyDir + "Alte DIN 1451 Mittelschrift.ttf");
MemoryFontSource memoryFontSource = new MemoryFontSource(fontBytes, 0);

Document doc = new Document();
doc.FontSettings = new FontSettings();
doc.FontSettings.SetFontsSources(new FontSourceBase[] {memoryFontSource});

Assert.AreEqual(FontSourceType.MemoryFont, memoryFontSource.Type);
Assert.AreEqual(0, memoryFontSource.Priority);

public MemoryFontSource(byte[] fontData, int priority)

byte[] fontBytes = File.ReadAllBytes(MyDir + "Alte DIN 1451 Mittelschrift.ttf");
MemoryFontSource memoryFontSource = new MemoryFontSource(fontBytes, 0);

Document doc = new Document();
doc.FontSettings = new FontSettings();
doc.FontSettings.SetFontsSources(new FontSourceBase[] {memoryFontSource});

Assert.AreEqual(FontSourceType.MemoryFont, memoryFontSource.Type);
Assert.AreEqual(0, memoryFontSource.Priority);

public MemoryFontSource(byte[] fontData, int priority, string cacheKey)

public void LoadFontSearchCache()
{
    const string cacheKey1 = "Arvo";
    const string cacheKey2 = "Arvo-Bold";
    FontSettings parsedFonts = new FontSettings();
    FontSettings loadedCache = new FontSettings();

    parsedFonts.SetFontsSources(new FontSourceBase[]
    {
        new FileFontSource(FontsDir + "Arvo-Regular.ttf", 0, cacheKey1),
        new FileFontSource(FontsDir + "Arvo-Bold.ttf", 0, cacheKey2)
    });

    using (MemoryStream cacheStream = new MemoryStream())
    {
        parsedFonts.SaveSearchCache(cacheStream);
        loadedCache.SetFontsSources(new FontSourceBase[]
        {
            new SearchCacheStream(cacheKey1),                    
            new MemoryFontSource(File.ReadAllBytes(FontsDir + "Arvo-Bold.ttf"), 0, cacheKey2)
        }, cacheStream);
    }

    Assert.AreEqual(parsedFonts.GetFontsSources().Length, loadedCache.GetFontsSources().Length);
}

/// <summary>
/// قم بتحميل بيانات الخط فقط عند الحاجة إليها بدلاً من تخزينها في الذاكرة
/// طوال عمر كائن "FontSettings".
/// </summary>
private class SearchCacheStream : StreamFontSource
{
    public SearchCacheStream(string cacheKey):base(0, cacheKey)
    {
    }

    public override Stream OpenFontDataStream()
    {
        return File.OpenRead(FontsDir + "Arvo-Regular.ttf");
    }
}