为了省去繁琐的原生富文本api调用，实现简单的封装。
NSMutableArray * array = [[NSMutableArray alloc] init];
[array addObject:[KBAttributedStringModel initWithText:@"我是红色字体" font:[UIFont systemFontOfSize:15] color: [UIColor redColor]]];
[array addObject:[KBAttributedStringModel initWithText:@" 我是绿色字体 " font:[UIFont systemFontOfSize:13] color: [UIColor greenColor]]];
[array addObject:[KBAttributedStringModel initWithText:@" 我是蓝色字体" font:[UIFont systemFontOfSize:16] color: [UIColor blueColor]]];
self.lableTest.attributedText = [KBAttributedStringTool conversionAttributedStringFromModelArray:array];