UICollectionView basics, uicollectionview

UICollectionView basics, uicollectionview

UICollectionView is often used in iOS development. UIScrollView is the same as UITableView, but operations are more complicated than UITableVIew. In some cases, you need to pay attention to the following details. //// ViewController. m // Collection # import "ViewController. h "# import" CollectionViewCell. h "# import" CollectionViewCell1.h "# import" CollectionReusableView. h "@ interface ViewController () <UICollectionViewDelegate, UICollectionViewDataSource> @ property (nonatomic, strong) UICollectionView * collectionView; @ end @ implementation ViewController-(void) viewDidLoad {[super viewDidLoad]; // The UICollectionViewFlowLayout object must be created here. * layout = [[UICollectionViewFlowLayout alloc] init]; // The minimum interval between two adjacent cells in the same row is layout. minimumInteritemSpacing = 5; // The interval between the minimum two rows is layout. minimumLineSpacing = 5; _ collectionView = [[UICollectionView alloc] initWithFrame: CGRectMake (0, 0,375,667) collectionViewLayout: layout]; _ collectionView. backgroundColor = [UIColor whiteColor]; _ collectionView. delegate = self; _ collectionView. dataSource = self; // This is a horizontal slide // layout. scrollDirection = uicollectionviewscrolldirehorhorizontal; [self. view addSubview: _ collectionView];/** this is the focus of cell registration. * // This type of cell is created by xib. You need to register UINib * cellNib = [UINib nibWithNibName: @ "CollectionViewCell" bundle: nil]; [_ collectionView registerNib: cellNib forCellWithReuseIdentifier: @ "CollectionViewCell"]; // This is the registration of a custom cell without xib // [_ collectionView registerClass: [CollectionViewCell1 class] forCellWithReuseIdentifier: @ "myheidentifier"]; // register the native cell. // [_ collectionView registerClass: [UICollectionViewCell class] forCellWithReuseIdentifier: @ "cell"]; // This is the registration UINib * cellNib1 = [UINib nibWithNibName: @ "CollectionReusableView" bundle: nil]; [_ collectionView registerNib: cellNib1 environment: Environment: @ "CollectionReusableView"]; [_ collectionView registerNib: cellNib1 metadata: Invalid withReuseIdentifier: @ "CollectionReusableView"];} // The total number of groups-(NSInteger) Metadata :( UICollectionView *) collectionView {return 1;} // number of cells in each group-(NSInteger) collectionView :( UICollectionView *) collectionView numberOfItemsInSection :( NSInteger) section {return 10 ;} // What is each cell-(UICollectionViewCell *) collectionView :( UICollectionView *) collectionView cellForItemAtIndexPath :( NSIndexPath *) indexPath {CollectionViewCell * cell = [collectionView detail: @ "CollectionViewCell" forIndexPath: indexPath]; cell. label. text = [NSString stringWithFormat: @ "% ld", indexPath. section * 100 + indexPath. row]; cell. backgroundColor = [UIColor gradient]; return cell;} // head and foot loading-(UICollectionReusableView *) collectionView :( UICollectionView *) collectionView detail :( NSString *) kind atIndexPath :( NSIndexPath *) indexPath {UICollectionReusableView * view = [collectionView attributes: kind attributes: @ "CollectionReusableView" forIndexPath: indexPath]; UILabel * label = [[UILabel alloc] initWithFrame: CGRectMake (110, 20,100, 30)]; if ([kind isEqualToString: UICollectionElementKindSectionHeader]) {label. text = @ "Header";} else {label. text = @ "";} [view addSubview: label]; return view;} // the upper left and lower right margin of each Group-(UIEdgeInsets) collectionView :( UICollectionView *) collectionView layout :( UICollectionViewLayout *) collectionViewLayout insetForSectionAtIndex :( NSInteger) section {return UIEdgeInsetsMake (5, 5, 5, 5);} // the size of the header attempt-(CGSize) collectionView :( UICollectionView *) collectionView layout :( UICollectionViewLayout *) collectionViewLayout referenceSizeForHeaderInSection :( NSInteger) section {return CGSizeMake (50, 60);} // the size of the foot (CGSize) collectionView :( UICollectionView *) collectionView layout :( UICollectionViewLayout *) collectionViewLayout referenceSizeForFooterInSection :( NSInteger) section {return CGSizeMake (50, 60);} // defines the size of each cell (CGSize) collectionView :( UICollectionView *) collectionView layout :( UICollectionViewLayout *) collectionViewLayout sizeForItemAtIndexPath :( NSIndexPath *) indexPath {return CGSizeMake (115,100);} // cell Click Event-(void) collectionView :( UICollectionView *) collectionView didSelectItemAtIndexPath :( NSIndexPath *) indexPath {// The animation after the cell is clicked [collectionView selectItemAtIndexPath: indexPath animated: YES scrollPosition: Finished];} @ end