如何使用c#从adobeillustrator (.ai) TextFrame中获取字体大小

我在c#中使用Adobe Illustrator库成功读取了Adobe Illustrator文件，但我无法获得TextFrame的FontSize。有人能帮忙吗?下面是我使用的代码:

Illustrator.Application aiApp = new Illustrator.Application();
Illustrator.Document doc =  aiApp.Open(@"K:'test'test.ai",Illustrator.AiDocumentColorSpace.aiDocumentRGBColor, null);
        List<Label> _labela = new List<Label>();
        int cntr = 0; 
        foreach (TextFrame tf in doc.TextFrames)
        {
            _labela.Add(new Label());
           // caktojme vetite per secilen label
            _labela[cntr].Name = "lblTextFrame" + cntr;
            _labela[cntr].AutoSize = true;
            _labela[cntr].Text = tf.Contents; 
            _labela[cntr].ForeColor = Color.FromArgb((int)tf.Layer.Color.Red, (int)tf.Layer.Color.Green, (int)tf.Layer.Color.Blue);
            _labela[cntr].Top = Math.Abs((int)tf.Top);
            _labela[cntr].Left = Math.Abs((int)tf.Left);
            cntr++;
        }
        foreach (Label lbl in _labela)
        {
            //lbl.BackColor = Color.Black; 
            this.Controls.Add(lbl);
            this.SuspendLayout(); 
            this.Refresh(); 
        }

    }

我没有看到TextFrame的任何属性。字形大小? ?(。有什么建议?

for (int i = 1; i <= doc.TextFrames.Count; i++)
{
    Illustrator.TextFrame tF = doc.TextFrames[i];
    Illustrator.TextFont objFont = tF.TextRange.CharacterAttributes.TextFont;
    double size = tF.TextRange.CharacterAttributes.Size;
    Console.WriteLine("Size: {0}, FontName: {1})", size, objFont.Name);
}