1.label設(shè)置行間距或者段間距 還有兩端對(duì)齊方式（label沒有該屬性）
2.label給指定字符串顯示指定的顏色、字體大小。下劃線等。

代碼

 //message

 NSMutableAttributedString * attributedString = [[NSMutableAttributedString alloc] initWithString:_message];
//樣式
 NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStyle alloc] init];
 //設(shè)置label每行文字之間的行間距   paragraphStyle.lineSpacing=3;
//設(shè)置文字兩端對(duì)齊
paragraphStyle.alignment=NSTextAlignmentJustified;
 NSDictionary * dic =@{
                          //這兩個(gè)一定要加哦。否則就沒效果啦
                          NSParagraphStyleAttributeName:paragraphStyle,
                          
                          NSUnderlineStyleAttributeName:[NSNumber numberWithInteger:NSUnderlineStyleNone],
                          NSFontAttributeName:[UIFont systemFontOfSize:14]
                          
                          };
 //富文設(shè)置樣式                      
 [attributedString setAttributes:dic range:NSMakeRange(0, attributedString.length)];
                          
 //設(shè)置                          
  _labelmessage.attributedText = attributedString;

計(jì)算高度

     CGSize titleSize = [mStr boundingRectWithSize:CGSizeMake(SCREEN_WIDTH - 16 * 2, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin context:nil].size;