单元格不出现在UITableViewController中

Question

I'm having an issue with displaying cells in my UITableViewController , simply..nothing shows up when I go to test. Below is my code.

FormationViewController.m

#import <Foundation/Foundation.h>
#import "FormationViewController.h"

@interface FormationViewController ()

@end

@implementation FormationViewController

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView
 numberOfRowsInSection:(NSInteger)section {
    return [self.names count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView
         cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Title"
                                                            forIndexPath:indexPath];

    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                      reuseIdentifier:@"Title"];
    }

    NSString *name = _names[indexPath.row];
    cell.textLabel.text = [NSString stringWithFormat:@"%@", name];
    return cell;
}

- (void)        tableView:(UITableView *)tableView
  didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

}

- (id)initWithNibName:(NSString *)nibNameOrNil
               bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    if (self) {
        self.title = @"Formation View";
        self.tabBarItem.image = [UIImage imageNamed:@"tab_icon_formation"];
        self.names = @[@"John Doe", @"Lee Harvey Oswald", @"Pat Buchanan", @"Angry Orchard",
                       @"Sierra Nevad", @"Jeff Bridges", @"John McClain", @"Lucy Genero"];
    }

    return self;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    NSLog(@"The length of names is %lu", self.names.count);
}

- (void)viewWillLayoutSubviews {
    [super viewWillLayoutSubviews];

    self.formationVC.frame = CGRectMake(
                                        0,
                                        self.topLayoutGuide.length,
                                        CGRectGetWidth(self.view.frame),
                                        CGRectGetHeight(self.view.frame)
                                        - self.topLayoutGuide.length
                                        - self.bottomLayoutGuide.length
                                        );
}

- (void)loadView {
    UIView *view = [[UIView alloc] init];
    view.backgroundColor = [UIColor whiteColor];

    self.formationVC = [[UIView alloc] init];
    self.formationVC.backgroundColor = [UIColor whiteColor];
    [view addSubview:self.formationVC];

    self.view = view;
}


- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
}

- (UIStatusBarStyle)preferredStatusBarStyle {
    return UIStatusBarStyleLightContent;
}
@end

And my FormationViewController.h

#import <UIKit/UIKit.h>

@interface FormationViewController : UITableViewController

@property (strong, nonatomic) UIView *formationVC;
@property (strong, nonatomic) NSArray *names;

@end

I'm also not sure if I'm putting some of these lines of code in the right methods.

I also think that my problem might be lying in the tableView:cellForRowAtIndexPath: method. I'm not absolutely sure I'm implementing that 100% correctly.

If anyone can help me find out what I'm doing wrong please let me know. This is my first Obj-C/iOS project I'm working on too so please be gentle! Thank you!

Answer 1

Well, I tried your code , using no xibs and faced the same problem. Then I changed 2 things

removed LoadView. moved self.names intialization from initWithNibName to viewDidLoad

added

[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"Title"];
[self.tableView reloadData];

to viewDidload And it worked

Answer 2

我认为您永远不会停止在(id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil ...如果从情节(id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil实例化视图控制器，则需要实现initWithCoder ，或者只将名称初始化在viewDidLoad 。

Answer 3

As you are probably using Storyboard, check these steps:

1) Storyboard - select your table view controller and in Identity Inspector make sure you have it's class set to your FormationVC.

2) Storyboard - select table view inside the controller and select it's first cell (suggesting you use Prototype Cells). Make sure it's style is set to Basic and set it's identifier for example to "BasicCell".

3) Go to your code and use this:

FormationVC.h

#import <UIKit/UIKit.h>
@interface FormationVC : UITableViewController
@end

FormationVC.m

#import "FormationVC.h"
@interface FormationVC ()
@property (strong, nonatomic) NSArray *names;
@end

@implementation FormationVC

#pragma mark - View Lifecycle

- (void)viewDidLoad {
    [super viewDidLoad];

    // you must not forget to call your custom init method once the view is loaded
    [self setupView];
}

- (void)setupView {

    // set title of VC
    self.title = @"Formation View";

    // create array of names
    _names = @[@"John Doe", @"Lee Harvey Oswald", @"Pat Buchanan", @"Angry Orchard",
               @"Sierra Nevad", @"Jeff Bridges", @"John McClain", @"Lucy Genero"];

    // log number of names in names array
    NSLog(@"The length of names is %lu", _names.count);

}

#pragma mark - Table View

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [_names count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"BasicCell" forIndexPath:indexPath];

    cell.textLabel.text = [NSString stringWithFormat:@"%@", _names[indexPath.row]];

    return cell;
}

@end

Answer 4

Problem IS there :-

@property (strong, nonatomic) NSArray *names;

change NSArray To NSMutableArray

in.h

EX:- @property (nonatomic , retain) NSMutableArray *names

and in.m

names = [[NSMutableArray alloc] init];

and then alloc init your Array and then put value its work .