How to specify a font for Text? about dxf HOT 2 OPEN

Presumably this is for display purposes in AutoCAD? First, I'll say that AutoCAD is really particular about what values it will accept and what ones it won't, so everything below this point is pure theory because I don't have AutoCAD available to test this with, but as I get time I can try it with LibreCAD.

The TextStyleName property on a TEXT entity needs to have a corresponding entry in the Styles property of DxfFile, and in that DxfStyle entry you'd specify the font in the PrimaryFontFileName property. E.g., something like this:

// n.b., this is untested, but you get the idea

var file = new DxfFile();

var myTextStyle = new DxfStyle("MY_STYLE_NAME");
myTextStyle.PrimaryFontFileName = "the-font-name-that-i-want-to-use";
file.Styles.Add(myTextStyle);

var text = new DxfText("this is a text entity");
text.TextStyleName = myTextStyle.Name; // you could also directly set it to "MY_STYLE_NAME"
file.Entities.Add(text);

from dxf.

Btw, it's the best way to add text - declare your style and then use it anywhere you need a text in dxf file. The STANDARD style does not explicitly specify a font to use, and sometimes Autocad shows wrong characters with STANDARD style.
I ended up specifying Consolas font explicitly

from dxf.