TableView 单元格不显示信息

Posted 2023-02-27

【中文标题】TableView 单元格不显示信息

【英文标题】：TableView Cells not displaying info

【发布时间】：2014-05-07 17:25:27

【问题描述】：

我的设置： 我有一个 UIViewController，其中插入了一个 TableView。同样在 viewController 我有一个文本字段和一个滑块。我正在尝试从我的文本字段中保存数据，存储它，然后让获取请求使用放置在 textField 中的任何信息填充单元格。但是，当我点击保存按钮时，tableCell 中没有任何内容。下面的 .m 文件属于我的 UIVeiwController。任何关于为什么单元格没有填充的帮助都会很好。谢谢！

    #import "BottleViewController.h"
    #import "LogEntry.h"
    #import "CoreDataStack.h"


    @interface BottleViewController () <NSFetchedResultsControllerDelegate>

    @property (strong, nonatomic) IBOutlet UILabel *ouncesLabel;
    @property (strong, nonatomic) UISlider *slider;
    @property (strong, nonatomic) NSFetchedResultsController *fetchedResultsController;
    @property (strong, nonatomic) IBOutlet UITableView *tableView;
    @property (strong, nonatomic) IBOutlet UILabel *entryAmount;
    @property (strong, nonatomic) IBOutlet UITextField *textField;

    @end

    @implementation BottleViewController



    - (void)viewDidLoad
    
        [super viewDidLoad];

        [self.fetchedResultsController performFetch:nil];
    

    -(void)dismissSelf

        [self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
    

    -(void)insertLogEntry 
        CoreDataStack *coreDataStack = [CoreDataStack defaultStack];
        LogEntry *entry = [NSEntityDescription insertNewObjectForEntityForName:@"LogEntry" inManagedObjectContext:coreDataStack.managedObjectContext];
        entry.amount = self.slider.value;
        entry.date = [[NSDate date] timeIntervalSince1970];
        entry.testString = self.textField.text;

        [coreDataStack saveContext];

    

    - (IBAction)backWasPressed:(id)sender 
        [self dismissSelf];
    






    - (IBAction)mySlider:(id)sender 
        self.slider = (UISlider*)sender;
        NSString *newText = [[NSString alloc] initWithFormat:@"%d", (int)self.slider.value];

        self.ouncesLabel.text = newText;

    
    - (IBAction)saveWasPressed:(id)sender 
        [self.view endEditing:YES];
        [self insertLogEntry];
    

    -(NSFetchRequest *)entryListFetchRequest
        NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:@"LogEntry"];
        fetchRequest.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"date" ascending:NO]];


        return fetchRequest;
    

    -(NSFetchedResultsController *)fetchedResultsController
        if(_fetchedResultsController != nil)
            return _fetchedResultsController;
        

        CoreDataStack *coreDataStack =[CoreDataStack defaultStack];
        NSFetchRequest *fetchRequest = [self entryListFetchRequest];

        _fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:coreDataStack.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
        _fetchedResultsController.delegate = self;

        return _fetchedResultsController;

    

    #pragma mark UITableViewDelegates

    -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView

        return self.fetchedResultsController.sections.count;

    

    -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

        id<NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultsController sections][section];
        return [sectionInfo numberOfObjects];

    

    -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

        static NSString *CellIdentifier =@"Cell";
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

        LogEntry *entry = [self.fetchedResultsController objectAtIndexPath:indexPath];


        cell.textLabel.text = entry.testString;


        return cell;
    

    -(void)controllerDidChangeContent:(NSFetchedResultsController *)controller
        [self.tableView reloadData];
    


    @end

【参考方案1】：

没关系。我忘了连接数据源和委托。