UITableView委托方法没有被调用？

Question

I' m trying to extract the UITableView Delegate method into a base class called BaseTableProvider

//BaseTableProvider.h
@protocol RSTableProviderProtocol <NSObject>

- (void)cellDidPress:(NSIndexPath *) atIndexPath;

@optional
- (void)cellNeedsDelete:(NSIndexPath *) atIndexPath;

@end

@interface RSBaseTableProvider : NSObject <UITableViewDelegate, UITableViewDataSource>

@property (nonatomic, strong) NSMutableArray *dataSource;
@property (nonatomic, weak) id<RSTableProviderProtocol> delegate;

@end
//BaseTableProvider.m
@implementation RSBaseTableProvider
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return 0;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    UITableViewCell *cell = [[UITableViewCell alloc]init];
    return cell;
}
@end

And then I create a subclass of BaseTableProvider, and override two UITableViewDelegate Method in the subclass

//RSFeedListTableProvider.h
@interface RSFeedListTableProvider : RSBaseTableProvider

@end

//RSFeedListTableProvider.m
@implementation RSFeedListTableProvider

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return [self.dataSource count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    RSFeedCell *cell = (RSFeedCell *)[tableView dequeueReusableCellWithIdentifier:kFeedCell];

    if(cell == nil){
        cell = [[RSFeedCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:kFeedCell];
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    }

    Feed *feed = (Feed *)self.dataSource[indexPath.row];

    if (feed != nil) {
        cell.titleText = feed.title;
        cell.subTitleText = feed.summary;
    }


    return cell;
}

@end

I initialized the ListTablerProvider in a ViewController.

//RSFeedListViewController.m
@implementation RSFeedListViewController

- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{
    _feedListView = [[RSFeedListView alloc] init];

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    _provider = [[RSFeedListTableProvider alloc] init];
    _provider.delegate = self;

    return self;
}

#pragma mark -- Life Cycle

- (void)loadView{
    RSFeedListView *aView = [[RSFeedListView alloc] initWithFrame:[UIScreen mainScreen].bounds];

    self.feedListView = aView;
    self.view = aView;

    self.feedListView.tableView.delegate = _provider;
    self.feedListView.tableView.dataSource = _provider;
}

But I can't see the cell built on the screen.I debuged the code found that UITableView Delegate Method in RSFeedListTableProvider was not called.Any one can help me?Thanks!

Answer 1

Maybe you are inherited NSObject instead UITableViewController! And you need to create property UITableView *tableView, and connect to your UITableViewController dataSource and delegate.

Answer 2

I think you did not implement the numberOfRowsInSection datasource method in your subclass RSFeedListTableProvider . So it will invoke the super class implementation

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return 0;
}

and there you are returning zero , so cellForRowAtIndexPath in your subclass never will be called.
Solution is implement numberOfRowsInSection in subclass and return proper count