uitableview卡顿问题处理

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;

CGSize strSize = [str boundingRectWithSize:CGSizeMake(BHSCREEN_W - 32, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:BH14Font} context:nil].size;
   return strSize.height+10;

NSMutableAttributedString *AttributedStr = [[NSMutableAttributedString alloc]initWithString:str];
           [AttributedStr addAttribute:NSFontAttributeName
                                 value:[UIFont systemFontOfSize:16.0]
                                 range:NSMakeRange(5, str.length-5)];
           [AttributedStr addAttribute:NSForegroundColorAttributeName
                                 value:[UIColor redColor]
                                 range:NSMakeRange(5, str.length-5)];
           _AmountPayableLabel.attributedText = AttributedStr;