iOS 计算label的高度

+ (CGFloat)labelHeight:(UILabel *)label lines:(NSInteger)lines

{

NSRange range = NSMakeRange(0, label.attributedText.length);

NSDictionary *dic = [label.attributedText attributesAtIndex:0 effectiveRange:&range];

CGSize size = CGSizeMake(label.bounds.size.width, 10000);

CGFloat height = [label.text boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:dic context:nil].size.height;

return height + 10.0f * lines;

}