Customized font with TTF files in WPF
===

Do I need anything else other than the TTF files to make customized fonts in WPF? I added my TTF files as existing items under the project and try to call them with "FontFamily ="abc.ttf" for TextBlocks, Treeviews and so on. Even thought there is no error reported, my window does not load the fonts either. Whatever font I set up before would be loaded. Is there any step I missed or something? I have seen over the web to do it with Blend but I only have Visual Studio 2010..... I did set the BUild Action of the ttf files to Content.....