获取字符宽度：并非自适应。coretext去计算

获取字符宽度：并非自适应。coretext去计算

UniChar ch = [ns_str characterAtIndex:0];

    CGGlyph glyph = 0;

    CTFontGetGlyphsForCharacters(fontRef, &ch, &glyph, 1);

    CGSize glyphSize;

    CTFontGetAdvancesForGlyphs(fontRef, kCTFontHorizontalOrientation, &glyph, &glyphSize, 1);