創建視圖控制器+的CollectionView程序並將其添加到滾動型

Question

我有一個簡短的問題。我想以編程方式創建一個ViewController，它具有UICollectionView，並將其添加到ScrollView。如果我使用Interfacebuilder執行此操作，則一切正常。但創建實例並以編程方式添加它不起作用，CollectionView不會顯示。這裏是我的代碼的一部分：

ViewController.m

ViewControllerCell* Cell = [[ViewControllerCell alloc]init]; 
[_contentScrollView addSubview:Cell.view]; 

ViewControllerCell.m

- (void)viewDidLoad{ 

    [super viewDidLoad]; 

    [self.view addSubview:self.collectionView]; 
    [self.view setBackgroundColor:[UIColor lightGrayColor]]; 
} 

淺灰色的背景出現了，所以我認爲，該子視圖中添加，但不知何故我的collectionview沒有出現。任何人都可以幫我嗎？

Answer 1

檢查您要添加的委託方法正確

@interface ViewController : UIViewController<UICollectionViewDataSource,UICollectionViewDelegateFlowLayout> 
{ 
    UICollectionView *_collectionView; 
} 

- (void)viewDidLoad { 
    UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init]; 
    _collectionView=[[UICollectionView alloc] initWithFrame:self.view.frame collectionViewLayout:layout]; 
    [_collectionView setDataSource:self]; 
    [_collectionView setDelegate:self]; 

    [_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cellIdentifier"]; 
    [_collectionView setBackgroundColor:[UIColor redColor]]; 

    [self.view addSubview:_collectionView]; 

    [super viewDidLoad]; 
    // Do any additional setup after loading the view, typically from a nib. 
} 

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section { 
    return 10; 
} 

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath { 
    UICollectionViewCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"cellIdentifier" forIndexPath:indexPath]; 

    cell.backgroundColor=[UIColor blueColor]; 
    return cell; 
} 

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath 
{ 
    return CGSizeMake(40, 40); 
}