UILabel（文本）

@property (nonatomic, strong) UILabel *Lab;

- (UILabel *)Lab {
    if (!_Lab) {
        UILabel *label = [[UILabel alloc] init];
        label.textAlignment = NSTextAlignmentRight;
        label.font = systemFont(16);
        label.text = @"label";
        label.backgroundColor = [UIColor whiteColor];
        label.numberOfLines = 2;
        _Lab = label;
    }
    return _Lab;
}

 [self.Lab mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.equalTo(self.view);
        make.height.equalTo(@30);
        make.width.equalTo(@30);
    }];

其他属性

##字体的设置
self.label.font = [UIFont fontWithName:@"Zapfino" size:20];
###UILable“中文”加上“英文或者其他非中文字符”自动换行的问题，结尾自动换行问题
self.labTitle.lineBreakMode = NSLineBreakByCharWrapping;
###文字大小自适应标签宽度 
self.labTitle.adjustsFontSizeToFitWidth = YES;//当文字超出标签宽度时，自动调整文字大小，使其不被截断

sizeToFit 与 sizeThatFit
https://blog.csdn.net/huangfei711/article/details/77435614
自定义UILabel
http://www.jianshu.com/p/554f88e4b731
计时UILabel
https://github.com/mineschan/MZTimerLabel

获取系统字体名称：

NSArray *familyNames = [UIFont familyNames];
for( NSString *familyName in familyNames )
{
    NSArray *fontNames = [UIFont fontNamesForFamilyName:familyName];
    for( NSString *fontName in fontNames )
    {
        printf( "\tFont: %s \n", [fontName UTF8String] );
    }
}