iOS中lebel特殊字符的自动换行问题解决

 let label = UILabel();
 var text = "七秒记忆鱼儿注，转发请备注七秒注,么么哒！";
 label.numberOfLines = 0;
 label.font = UIFont.systemFont(ofSize: 15);
 let size = text.wj_computedTextHeight(font: 15, size: CGSize.init(width: view.bounds.width, height: CGFloat(MAXFLOAT)));
 var text1 = text;
 text.append("七秒最帅");
 let size1 = text.wj_computedTextHeight(font: 15, size: CGSize.init(width: view.bounds.width, height: CGFloat(MAXFLOAT)));
 if size.height != size1.height {
 text1.append("\n");
 text1.append("七秒最帅");
 text = text1;
 }
 label.text = text;
 label.frame = CGRect.init(x: 10, y: 64, width: size1.width, height: size1.height);
 view.addSubview(label);

/// 计算文字的size
///
/// - parameter font: 大小
/// - parameter size: 文本的打下
///
/// - returns: 返回size
func wj_computedTextHeight(font:CGFloat,size:CGSize)->CGSize{
 print(self,size);
 let str = self as NSString;
 let maxSize = str.boundingRect(with: size, options:NSStringDrawingOptions.usesLineFragmentOrigin, attributes: [NSFontAttributeName:UIFont.systemFont(ofSize: font)], context: nil).size

 return maxSize;
}