Ios 我的UICollectionView不调用其数据源方法？

我刚刚得到了一个带有

UICollectionView

的标准

UIViewController

子类。该

UICollection

视图未调用其数据源（或委托）方法，但我看不出缺少哪一部分

以下是显示UICollectionView的my UIViewController类的接口：

@interface PastViewController ()  <UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout>
...
@property (nonatomic, weak) UICollectionView *collectionView;
@end

最后，我还将发布数据源、委托和委托流布局协议。没有其他子视图添加到视图控制器，我已设置了委托并声明了委托协议，因此以下so帖子不适用：

我错过了什么？为什么永远不会调用数据源方法（和委托方法）

以下是针对各种协议实施的方法：

#pragma mark - UICollectionViewDataSource

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{

    NSLog(@"should be seeing %d collection view cells", self.complaints.count);
    return self.complaints.count;
}


- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView{
    NSLog(@"QUERYING NUMBER OF SECTIONS IN COLLECTION VIEW");
    return 1;
}


- (UICollectionViewCell  *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    VideoCollectionViewCell *cell = [[VideoCollectionViewCell alloc] initWithCoder:@"cell"];
    cell.complaint = self.complaints[indexPath.row];
    return cell;
}


#pragma mark - UICollectionViewDelegate

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
    NSLog(@"calling didselctitem at path");
}

- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath{
    NSLog(@"diddeselectitem");
}


#pragma mar - UICollectionViewFlowDelegateLayout

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{
    return CGSizeMake(100, 100);
}


- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{
    return UIEdgeInsetsMake(50, 20, 50, 20);
}

@property（非原子，强）UICollectionView*collectionView

将
weak
更改为
strong
，或
collectionView
将在赋值后发布，这意味着
collectionView
将为
nil
，因此永远不会调用数据源方法

另一种方法：

保持
collectionView
为
弱

- (void)viewDidLoad {

    [super viewDidLoad];    


    UICollectionViewFlowLayout* flowLayout = [[UICollectionViewFlowLayout alloc]init];
    flowLayout.itemSize = CGSizeMake(100, 100);
    [flowLayout setScrollDirection:UICollectionViewScrollDirectionHorizontal];

    //self.complaints is used to generate the collection view cells
    //the log always prints out 30 complaints
    self.complaints = [self.complaintDatabase getComplaints ];
    NSLog(@"got a total OF %d complaints", self.complaints.count);

    UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, self.width, self.height) collectionViewLayout:flowLayout];
    collectionView.delegate = self;
    collectionView.dataSource = self;
    [collectionView registerClass:[VideoCollectionViewCell class] forCellWithReuseIdentifier:@"cell"];
    [self.view addSubview:collectionView];
    self.collectionView = collectionView;

    [self.collectionView reloadData];
    [self.collectionView reloadInputViews];
}

请参阅：
不应声明属性strong。而是使用新的集合视图对象创建变量，将其添加到控制器视图，然后将其分配给属性。
- (void)viewDidLoad {

    [super viewDidLoad];    


    UICollectionViewFlowLayout* flowLayout = [[UICollectionViewFlowLayout alloc]init];
    flowLayout.itemSize = CGSizeMake(100, 100);
    [flowLayout setScrollDirection:UICollectionViewScrollDirectionHorizontal];

    //self.complaints is used to generate the collection view cells
    //the log always prints out 30 complaints
    self.complaints = [self.complaintDatabase getComplaints ];
    NSLog(@"got a total OF %d complaints", self.complaints.count);

    UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, self.width, self.height) collectionViewLayout:flowLayout];
    collectionView.delegate = self;
    collectionView.dataSource = self;
    [collectionView registerClass:[VideoCollectionViewCell class] forCellWithReuseIdentifier:@"cell"];
    [self.view addSubview:collectionView];
    self.collectionView = collectionView;

    [self.collectionView reloadData];
    [self.collectionView reloadInputViews];
}