ios - 多选项卡 SegmentControl 的单个 CollectionView

Question

我想使用段 Controller 显示两个 Collection View ，在更改段时将显示第二个 Collection View 。我的代码是:

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{

UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"morningcell" forIndexPath:indexPath];
UICollectionViewCell *cell1 = [collectionView dequeueReusableCellWithReuseIdentifier:@"eveningcell" forIndexPath:indexPath];

if (_segment.selectedSegmentIndex == 0) {


    UILabel *lbl = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, cell.frame.size.height,cell.frame.size.width)];
    lbl.text = [numbers objectAtIndex:indexPath.row];
    [cell addSubview:lbl];
    [lbl setTextAlignment:UITextAlignmentCenter];
    return cell;
}
else{
    UILabel *lbl = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, cell1.frame.size.height,cell1.frame.size.width)];
    lbl.text = [numbers objectAtIndex:indexPath.row];
    [cell1 addSubview:lbl];
    [lbl setTextAlignment:UITextAlignmentCenter];
    return cell1;
}}

Answer 1

Do not create two collectionView for the task that you want because you can achieve it using a single collectionView.


@interface YourVC(), UICollectionViewDelegate, UICollectionViewDataSource {
NSArray *arrayOfModelsForFirstCollectionView;
NSArray *arrayOfModelsForSecondCollectionView;
}
@end
@implementation YourVC
-(void)viewDidLoad{
    [super viewDidLoad];
    //Fetch Data For both Segments Using Your Web API Call or Local Database API Call
}
-(IBAction)didChangeSegmentIndex:(id)sender{
    //When segment is changed you need to tell your collectionView to update the data.
    [self.collectionView reloadData];
}
-(NSInteger) collectionView:(UICollectionView *)collectionView numberOfRowsInSection:(NSInteger)section{
    //When reloadData is call this method will check that which index is selected.
   //And according to selection it will create number of cells.
    if (self.segmentControl.selectedIndex == 0){
        return arrayOfModelsForFirstCollectionView.count;
    }else{
        return arrayOfModelsForSecondCollectionView.count;
    }
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    //While creating a cell it will check which segment is selected so it will initialize and create the cell with respect to selection of segments.
    //Hence you have created two different cells in a single collectionView toggling with a segmentControl.
    if (_segment.selectedSegmentIndex == 0) {
        return [self makeCellForFirstSegmentAtIndexPath: indexPath];
    }
    else{
        return [self makeCellForSecondSegmentAtIndexPath: indexPath];
    }
}
-(UITableViewCell *)makeCellForFirstSegmentAtIndexPath:(NSIndexPath *)indexPath{
    //To show data from array you need to use arrayOfModelsForFirstCollectionView because this array is associated with First Segment Index
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"morningcell" forIndexPath:indexPath];
    UILabel *lbl = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, cell.frame.size.height,cell.frame.size.width)];
    lbl.text = [arrayOfModelsForFirstCollectionView objectAtIndex:indexPath.row];
    [cell addSubview:lbl];
    [lbl setTextAlignment:UITextAlignmentCenter];
    return cell;
}

-(UITableViewCell *)makeCellForSecondSegmentAtIndexPath:(NSIndexPath *)indexPath{
    //To show data from array you need to use arrayOfModelsForSecondCollectionView because this array is associated with Second Segment Index
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"eveningcell" forIndexPath:indexPath];
    UILabel *lbl = [[UILabel alloc]initWithFrame:CGRectMake(0, 0,   cell.frame.size.height,cell.frame.size.width)];
    lbl.text = [arrayOfModelsForSecondCollectionView objectAtIndex:indexPath.row];
    [cell addSubview:lbl];
    [lbl setTextAlignment:UITextAlignmentCenter];
    return cell;
}
@end