IOS计算Label的高度

```

+ (CGFloat)heighForText:(NSString *)string{

NSMutableAttributedString *attrStr = [[NSMutableAttributedString alloc] initWithString:string];

NSRange allRange = [string rangeOfString:string];

[attrStr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:14.0] range:allRange];

[attrStr addAttribute:NSForegroundColorAttributeName value:[UIColor darkGrayColor]range:allRange];

CGFloat titleHeight;

NSStringDrawingOptions options =  NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading;

//获取label的最大宽度

CGRect rect = [attrStr boundingRectWithSize:CGSizeMake([UIScreen mainScreen].bounds.size.width - 30, CGFLOAT_MAX)options:options context:nil];

titleHeight = ceilf(rect.size.height);

return titleHeight;

}

```