需求：中間紅色框?yàn)闄M向滾動(dòng)的collectionView（前一場(chǎng)/后一場(chǎng)的可用：當(dāng)前第0場(chǎng)僧界，前一場(chǎng)不可用节腐；當(dāng)前最后一場(chǎng)猜揪，后一場(chǎng)不可用）。

1. 點(diǎn)擊前一場(chǎng)/后一場(chǎng)， collectionView滾動(dòng)到對(duì)應(yīng)位置聋庵，中間顯示當(dāng)前選擇時(shí)間膘融，控制前一場(chǎng)/后一場(chǎng)是否可用
2. 滾動(dòng)collectionView，控制前一場(chǎng)/后一場(chǎng)是否可用祭玉，中間顯示當(dāng)前選擇時(shí)間
3. 選擇pickerView氧映，collectionView滾動(dòng)到對(duì)應(yīng)位置，控制前一場(chǎng)/后一場(chǎng)是否可用脱货，中間顯示當(dāng)前選擇時(shí)間

效果.jpg

點(diǎn)擊時(shí)間岛都，彈出pickerView與遮罩.jpg

1. 設(shè)置默認(rèn)顯示：

- (void)viewDidLoad {
    [super viewDidLoad];
    // 默認(rèn)顯示第最后一場(chǎng)，此時(shí)不能加collectionView的滾動(dòng)動(dòng)畫
    _currentScreening = self.movieHallSeatModels.count-1;
    [self showDataWithCurrentScreening:_currentScreening animated:NO];
}

2. 點(diǎn)擊前一場(chǎng)：

- (void)didClickLastFilmBtn {
    
    if (_currentScreening == 0) return;

    _currentScreening--;
    [self showDataWithCurrentScreening:_currentScreening animated:YES];
}

3. 點(diǎn)擊后一場(chǎng)：

- (void)didClickNextFilmBtn {
    
    if (_currentScreening == self.movieHallSeatModels.count-1) return;
    
    _currentScreening++;
    [self showDataWithCurrentScreening:_currentScreening animated:YES];
}

4. 點(diǎn)擊時(shí)間振峻，彈出pickerView臼疫，并選中到當(dāng)前場(chǎng)次：

- (void)didClickChooseTimeBtn {
    
    [self.view addSubview:self.maskview];
    [self.maskview addSubview:self.chooseTimeView];
    
    CGFloat y = SCREEN_HEIGHT - FYChooseTimeView_H;
    CGFloat height = FYChooseTimeView_H;
    [UIView animateWithDuration:0.3 animations:^{
        self.chooseTimeView.frame = CGRectMake(0, y, SCREEN_WIDTH, height);
    }];
    
    // pickerView顯示當(dāng)前選中場(chǎng)次
    [self.timePickerView selectRow:_currentScreening inComponent:0 animated:NO];
}

選中pickerView的代理方法 ：
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
    _chosenRow = row;
    _currentScreening = row;
    _chosenTimeStr = self.chooseTimes[row];
}

點(diǎn)擊確定：
- (void)didClickConfirmTimeBtn {
    
    [self showDataWithCurrentScreening:_chosenRow animated:YES];
    [self didClickMaskviewBtn];
}

核心方法：

- (void)showDataWithCurrentScreening:(NSInteger)index animated:(BOOL)animated{
    // 設(shè)置可用
    [self isFilmBtnEnableWithButton:self.lastFilmBtn condition:0];
    [self isFilmBtnEnableWithButton:self.nextFilmBtn condition:self.movieHallSeatModels.count-1];

    // 設(shè)置顯示時(shí)間，及pickView的選中
    _chosenTimeStr = self.chooseTimes[index];
    [self.chooseTimeBtn setTitle:_chosenTimeStr forState:UIControlStateNormal];
    [self.timePickerView selectRow:_currentScreening inComponent:0 animated:NO];
    
    // 滾動(dòng)到指定cell
    NSIndexPath *indexPath = [NSIndexPath indexPathForItem:_currentScreening inSection:0];
    [self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:animated];

}
- (void)isFilmBtnEnableWithButton:(UIButton *)button condition:(NSInteger)index{
    
    if (_currentScreening == index) {
        button.userInteractionEnabled = NO;
        button.alpha = 0.4;
    }else {
        button.userInteractionEnabled = YES;
        button.alpha = 1;
    }
}

5. 滾動(dòng)collectionView扣孟，顯示對(duì)應(yīng)場(chǎng)次烫堤，且控制collectionView滾動(dòng)不足半個(gè)屏幕的時(shí)候跳回到上一個(gè)，滾動(dòng)超過(guò)半個(gè)屏幕跳到下一個(gè)：

- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
    // 獲取滾動(dòng)的當(dāng)前位置
    CGPoint originalTargetContentOffset = CGPointMake(targetContentOffset->x, targetContentOffset->y);
    CGPoint targetCenter = CGPointMake(originalTargetContentOffset.x + CGRectGetWidth(self.collectionView.bounds)/2, CGRectGetHeight(self.collectionView.bounds) / 2);
    NSIndexPath *indexPath = nil;
    NSInteger i = 0;
    while (indexPath == nil) {
        targetCenter = CGPointMake(originalTargetContentOffset.x + CGRectGetWidth(self.collectionView.bounds)/2 + 10*i, CGRectGetHeight(self.collectionView.bounds) / 2);
        indexPath = [self.collectionView indexPathForItemAtPoint:targetCenter];
        i++;
    }
     _currentScreening = indexPath.item;
    
    // 設(shè)置對(duì)應(yīng)顯示
    _chosenTimeStr = self.chooseTimes[_currentScreening];
    [self.chooseTimeBtn setTitle:_chosenTimeStr forState:UIControlStateNormal];
    [self isFilmBtnEnableWithButton:self.lastFilmBtn condition:0];
    [self isFilmBtnEnableWithButton:self.nextFilmBtn condition:self.movieHallSeatModels.count-1];
    [self.timePickerView selectRow:_currentScreening inComponent:0 animated:NO];
    
    // 調(diào)轉(zhuǎn)到指定位置
    UICollectionViewLayoutAttributes *attributes = [self.collectionView.collectionViewLayout layoutAttributesForItemAtIndexPath:indexPath];
    if (attributes) {
        *targetContentOffset = CGPointMake(attributes.center.x - CGRectGetWidth(self.collectionView.bounds)/2, originalTargetContentOffset.y);
    }
}