objective-c - プログラムで作成されたテーブルビューは空です

Question

Tableview が表示されますが、空です。何を忘れたのか理解できません。

#import <UIKit/UIKit.h>

@interface MenuViewController : UIViewController<UITableViewDataSource, UITableViewDelegate>
@property (strong, nonatomic) UITableView *table;
@end


#import "MenuViewController.h"

@interface MenuViewController ()

@end

@implementation MenuViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    _table.delegate = self;
    _table.dataSource = self;
    _table = [[UITableView alloc]initWithFrame:self.view.bounds style:UITableViewStylePlain];
    [self.view addSubview:_table];
    // Uncomment the following line to preserve selection between presentations.
    // self.clearsSelectionOnViewWillAppear = NO;

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    NSLog(@"%s",__PRETTY_FUNCTION__);
    [_table reloadData];
}
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    return 4;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    if (cell == nil) {

        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];

    }

    cell.textLabel.text = @"text";

    // Configure the cell...

    return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return 25;
}

Answer 1

In viewDidLoad you are assigning the dataSource and delegate of the _table variable before instantiating it. So when you initialize the _table variable it is overwriting anything that is already there.

If you move the initialization call before the assignment of the delegate and data source it should work correctly:

- (void)viewDidLoad
{
    [super viewDidLoad];
    _table = [[UITableView alloc]initWithFrame:self.view.bounds style:UITableViewStylePlain];
    _table.delegate = self;
    _table.dataSource = self;
    [self.view addSubview:_table];
}

Answer 2

Just comment this line:

[self.view addSubview:_table];