需求：中间红色框为横向滚动的collectionView（前一场/后一场的可用：当前第0场，前一场不可用；当前最后一场，后一场不可用）。
1. 点击前一场/后一场， collectionView滚动到对应位置，中间显示当前选择时间，控制前一场/后一场是否可用
2. 滚动collectionView，控制前一场/后一场是否可用，中间显示当前选择时间
3. 选择pickerView，collectionView滚动到对应位置，控制前一场/后一场是否可用，中间显示当前选择时间
效果.jpg
点击时间，弹出pickerView与遮罩.jpg
1. 设置默认显示：
- (void)viewDidLoad {
[super viewDidLoad];
// 默认显示第最后一场，此时不能加collectionView的滚动动画
_currentScreening = self.movieHallSeatModels.count-1;
[self showDataWithCurrentScreening:_currentScreening animated:NO];
}
2. 点击前一场：
- (void)didClickLastFilmBtn {
if (_currentScreening == 0) return;
_currentScreening--;
[self showDataWithCurrentScreening:_currentScreening animated:YES];
}
3. 点击后一场：
- (void)didClickNextFilmBtn {
if (_currentScreening == self.movieHallSeatModels.count-1) return;
_currentScreening++;
[self showDataWithCurrentScreening:_currentScreening animated:YES];
}
4. 点击时间，弹出pickerView，并选中到当前场次：
- (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显示当前选中场次
[self.timePickerView selectRow:_currentScreening inComponent:0 animated:NO];
}
选中pickerView的代理方法 ：
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
_chosenRow = row;
_currentScreening = row;
_chosenTimeStr = self.chooseTimes[row];
}
点击确定：
- (void)didClickConfirmTimeBtn {
[self showDataWithCurrentScreening:_chosenRow animated:YES];
[self didClickMaskviewBtn];
}
核心方法：
- (void)showDataWithCurrentScreening:(NSInteger)index animated:(BOOL)animated{
// 设置可用
[self isFilmBtnEnableWithButton:self.lastFilmBtn condition:0];
[self isFilmBtnEnableWithButton:self.nextFilmBtn condition:self.movieHallSeatModels.count-1];
// 设置显示时间，及pickView的选中
_chosenTimeStr = self.chooseTimes[index];
[self.chooseTimeBtn setTitle:_chosenTimeStr forState:UIControlStateNormal];
[self.timePickerView selectRow:_currentScreening inComponent:0 animated:NO];
// 滚动到指定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. 滚动collectionView，显示对应场次，且控制collectionView滚动不足半个屏幕的时候跳回到上一个，滚动超过半个屏幕跳到下一个：
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
// 获取滚动的当前位置
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;
// 设置对应显示
_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];
// 调转到指定位置
UICollectionViewLayoutAttributes *attributes = [self.collectionView.collectionViewLayout layoutAttributesForItemAtIndexPath:indexPath];
if (attributes) {
*targetContentOffset = CGPointMake(attributes.center.x - CGRectGetWidth(self.collectionView.bounds)/2, originalTargetContentOffset.y);
}
}
