Jerky scroll UITableView

Question

我有一个非常复杂的UITableViewCell。它包含UITableView里面，很多自定义视图等。并且取决于cellType我在自定义单元格对象的layoutSubviews和updateConstraints方法中以编程方式设置了一些约束。所以很明显我有一个不稳定的卷轴，当我至少有5个单元格因为我的单元格很多次布局。在cellForRowAtIndexPath我为每个单元格调用

[cell setNeedsLayout];
[cell layoutIfNeeded];

如何优化UITableView？设置所有值后，是否可以只布置一次？提前致谢。我真的被困了。

编辑：

我真的忘了展示代码。

- (ReservationCell *)approvedReservationCellInTableView:(UITableView *)tableView atIndexPath:(NSIndexPath *)indexPath
                                   reservation:(Reservation *)reservation
{
    ReservationCell *cell = [tableView dequeueReusableCellWithIdentifier:kReservationCellXibAndReuseIdentifier forIndexPath:indexPath];
    cell.isTouchingDisabledInTimeView = NO;
    cell.indexPath = indexPath;
    cell.tableView = self.tableView;
    cell.bottomWrapper.indexPath = indexPath;

    UIImage *placeholderImage = [UIImage imageNamed:@"userpic_dark_with_border"];
    [cell.userpicImageView setImageWithURL:[NSURL URLWithString:reservation.guestInfo.userpic] placeholderImage:placeholderImage];

    [cell setStatus:reservation.status];

    cell.bottomWrapper.dataSource = self;
    cell.bottomWrapper.delegate = self;

    cell.nameLabel.text = reservation.guestInfo.fullName;
    cell.reserverNameLabel.text = reservation.bookedBy.fullName;
    cell.noteTextView.text = reservation.bookingNote.length > 0 ? reservation.bookingNote : @"";

    BOOL hasAssignedStaff = reservation.staff.count > 0;
    if (hasAssignedStaff) {
        NSMutableArray *staffArray = [[NSMutableArray alloc] init];
        for (SearchUserInfo *staffInfo in reservation.staff) {
            [staffArray addObject:staffInfo];
        }
        [self.staffDictionaryForIndexPath setObject:staffArray forKey:indexPath];
    }  else {
        [cell forceUpdateConstraints];
    }

    cell.delegate = self;
    cell.dataSource = self;


    cell.tableNameLabel.text = [self tableNameForReservation:reservation];
    cell.minValueLabel.text = [self minValueForReservation:reservation];
    cell.completionTimeLabel.text = reservation.estimatedArrivalTime.length > 1 ? [Tools timeWithAMPMFrom:reservation.estimatedArrivalTime] : @"--:--";
    cell.guestsCountLabel.text = [NSString stringWithFormat:@"%d / %d", (int)reservation.arrivedGirls + (int)reservation.arrivedGuys, (int)reservation.totalGuests];

    cell.bottomWrapper.shouldHideMenuButton = NO;
    cell.cellType = ReservationCellTypeApproved;

    [cell setNeedsLayout];
    [cell layoutIfNeeded];

    return cell;
}


- (void)setDataSource:(id<ReservationCellDataSource>)dataSource
{
    self->_dataSource = dataSource;
    [self.staffTableView reloadData];
    [self.collectionView reloadData];
    [self updateTagsWrapperConstraint];
    [self updateCompletedViewTopGraylineState];
}

- (void)updateCompletedViewTopGraylineState
{
    if ([self.dataSource respondsToSelector:@selector(staffNamesArrayInReservationCell:)]) {
        NSArray *names = [self.dataSource staffNamesArrayInReservationCell:self];
        NSArray *tagsArray = [self.dataSource tagsArrayInReservationCell:self];
        BOOL isCorrectStatus = self.reservationStatus == ReservationStatusCompleted
        || self.reservationStatus == ReservationStatusConfirmedComplete;
        if (names.count == 0 && tagsArray.count == 0 &&
            self.bottomWrapper.wrapperHeight == 0 && isCorrectStatus && self.noteTextView.text.length == 0) {
            self.completedView.topGrayLine.hidden = YES;
            self.completedViewTopConstraint.constant = 0.f;
        } else {
            self.completedView.topGrayLine.hidden = NO;
                if (self.bottomWrapper.wrapperHeight == 0) {
                    self.completedViewTopConstraint.constant = 9.f;
                } else {
                    self.completedViewTopConstraint.constant = 0.f;
                }
            self.completedViewTopConstraint.constant = 0.f;
        }
    }
}

- (void)configureConstraints
{
    if (self.cellType == ReservationCellTypeUndefined) {
        return;
    }

    CGFloat rightButtonsWrapperWidth = 0;
    CGFloat rightButtonsWrapperHeight = 0;

    CGFloat rithWrapperApproveWidth = 0;
    CGFloat rithWrapperApproveHeight = 0;

    CGFloat arrivedButtonWidth = 0;
    CGFloat arrivedButtonHeight = 0;

    if (self.cellType == ReservationCellTypeCustomersProfile) {
        if (self.reservationStatus == ReservationStatusPending) {
            //self.statusLabel.text = @"";
        }
        if (self.reservationStatus == ReservationStatusArrived) {

        }
    }

    if (self.cellType == ReservationCellTypeSeating) {
        if (self.reservationStatus == ReservationStatusArrived) {
            rightButtonsWrapperWidth = 100.f;
            rightButtonsWrapperHeight = 100.f;
        } else {
            rightButtonsWrapperWidth = 0;
            rightButtonsWrapperHeight = 0;
        }
    }

    if (self.cellType == ReservationCellTypePickReservation) {
        arrivedButtonWidth = 80.f;
        arrivedButtonHeight = 25.f;
    }

    if (self.cellType == ReservationCellTypePending) {
        if (self.reservationStatus == ReservationStatusPending) {
            rithWrapperApproveWidth = 45.f;
            rithWrapperApproveHeight = 115.f;
        }
    }

    if (self.cellType == ReservationCellTypeGuestlist) {
        rightButtonsWrapperWidth = 100.f;
        rightButtonsWrapperHeight = 100.f;
    }

    [self.rightButtonsWrapper mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.width.mas_equalTo(rightButtonsWrapperWidth);
        make.height.mas_equalTo(rightButtonsWrapperHeight);
    }];

    [self.rightWrapperApprove mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.width.mas_equalTo(rithWrapperApproveWidth);
        make.height.mas_equalTo(rithWrapperApproveHeight);
    }];

    if (self.cellType !=  ReservationCellTypeCustomersProfile) {
        if (self.reservationStatus == ReservationStatusCompleted || self.reservationStatus == ReservationStatusConfirmedComplete) {
            self.rightButtonsWrapperTopConstraint.constant = 0.f;
            self.rightWrapperApproveTopConstraint.constant = 0.f;
            CGFloat height = 0;
            if (self.cellType == ReservationCellTypeEndOfDay) {
                CGFloat labelHeight = [self labelHeight:self.completedView.completionCommentLabel];
                height = 202.f + labelHeight;
            }
            [self.completedView mas_remakeConstraints:^(MASConstraintMaker *make) {
                make.height.mas_equalTo(height);
            }];
        } else {
            [self.completedView mas_remakeConstraints:^(MASConstraintMaker *make) {
                make.height.mas_equalTo(0.f);
            }];
        }
    }
    BOOL isTypeForArrivedButton = self.cellType == ReservationCellTypeSeating || self.cellType == ReservationCellTypeEndOfDay;
    if (self.reservationStatus == ReservationStatusApproved && isTypeForArrivedButton) {
        arrivedButtonWidth = 80.f;
        arrivedButtonHeight = 25.f;
    }

    [self.arrivedButton mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.height.mas_equalTo(arrivedButtonHeight);
        make.width.mas_equalTo(arrivedButtonWidth);
    }];

//    if (self.cellType == ReservationCellTypePending) {
//        [self.rightWrapperApprove mas_remakeConstraints:^(MASConstraintMaker *make) {
//            make.bottom.mas_greaterThanOrEqualTo(self.bottomWrapper.mas_top).with.offset(10);
//        }];
//    }

    if (self.cellType == ReservationCellTypeSeating) {
        if (self.reservationStatus == ReservationStatusArrived) {
            [self addRightButtonsWrapperExcludedPathWidth:rightButtonsWrapperWidth height:rightButtonsWrapperHeight];
        }
    }

    if (self.cellType == ReservationCellTypeGuestlist) {
        [self addRightButtonsWrapperExcludedPathWidth:rightButtonsWrapperWidth height:rightButtonsWrapperHeight];
    }

    if (self.cellType == ReservationCellTypePending) {
        if (self.reservationStatus == ReservationStatusPending) {
            [self addRightWrapperApproveExcludedPathWidth:rithWrapperApproveWidth height:rithWrapperApproveHeight];
        }
    }

    [self updateTopLabelsViewHeightConstraint];
}