用于从属性读取的XCode No Getter方法的ToDoList教程-OBJ C

我已经看过几次XCode应用程序开发教程，并不断提出相同的错误。

source.ToDoItem给出错误“没有可从属性读取的吸气剂方法”

有关如何解决此问题的任何想法？我似乎无法编写正确的getter方法，也无法在开发教程中找到要使用的示例。

- (IBAction)unwindToList:(UIStoryboardSegue *)segue {
AddToDoItemViewController *source = [segue sourceViewController];
ToDoItem *item = source.ToDoItem;
if (item != nil) {
    [self.toDoItems addObject:item];
    [self.tableView reloadData];
}

}

ToDoItem.h

#import <Foundation/Foundation.h>

@interface ToDoItem : NSObject

@property NSString *itemName;
@property BOOL completed;
@property (readonly) NSDate *creationDate;

@end

ToDoItem.m

#import "ToDoItem.h"

@implementation ToDoItem

@end

ToDoListTableViewController

#import "ToDoListTableViewController.h"

#import "AddToDoItemViewController.h"
#import "ToDoItem.h"

@interface ToDoListTableViewController ()

@property NSMutableArray *toDoItems;

@end

@implementation ToDoListTableViewController

- (void)loadInitialData {
    ToDoItem *item1 = [[ToDoItem alloc] init];
    item1.itemName = @"things";
    [self.toDoItems addObject:item1];
    ToDoItem *item2 = [[ToDoItem alloc] init];
    item2.itemName = @"Things to do with things";
    [self.toDoItems addObject:item2];
    ToDoItem *item3 = [[ToDoItem alloc] init];
    item3.itemName = @"Write Ethics Paper";
    [self.toDoItems addObject:item3];

}

- (IBAction)unwindToList:(UIStoryboardSegue *)segue {
    AddToDoItemViewController *source = [segue sourceViewController];
    ToDoItem *item = source.ToDoItem;
    if (item != nil) {
        [self.toDoItems addObject:item];
        [self.tableView reloadData];
    }

}

- (void)viewDidLoad {
    [super viewDidLoad];

    self.toDoItems = [[NSMutableArray alloc] init];
    [self loadInitialData];

    // self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
#warning Potentially incomplete method implementation.
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
#warning Incomplete method implementation.
    // Return the number of rows in the section.
    return [self.toDoItems count];
}


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

    ToDoItem *toDoItem = [self.toDoItems objectAtIndex:indexPath.row];
    cell.textLabel.text = toDoItem.itemName;
    // Configure the cell...

    if (toDoItem.completed) {
        cell.accessoryType = UITableViewCellAccessoryCheckmark;
    } else {
        cell.accessoryType = UITableViewCellAccessoryNone;
    }

    return cell;

}


- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    [tableView deselectRowAtIndexPath:indexPath animated:NO];
    ToDoItem *tappedItem = [self.toDoItems objectAtIndex:indexPath.row];
    tappedItem.completed = !tappedItem.completed;
    [tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationNone];
}
@end

和ToDoListTableViewController.h

#import <UIKit/UIKit.h>
#import "ToDoItem.h"
#import "AddToDoItemViewController.h"

@interface ToDoListTableViewController : UITableViewController
- (IBAction)unwindToList:(UIStoryboardSegue *)segue;

@end

AddToDoItemViewController.m

#import "AddToDoItemViewController.h"
#import "ToDoItem.h"



@interface AddToDoItemViewController ()
@property (weak, nonatomic) IBOutlet UITextField *textField;

@property (weak, nonatomic) IBOutlet UIBarButtonItem *saveButton;


@end

@implementation AddToDoItemViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if (sender != self.saveButton) return;
    if (self.textField.text.length > 0) {
    }
    self.toDoItem = [[ToDoItem alloc] init];
    self.toDoItem.itemName = self.textField.text;
    self.toDoItem.completed = NO;
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}



@end

AddToDoItemViewController.h

#import <UIKit/UIKit.h>
#import "ToDoItem.h"

@interface AddToDoItemViewController : UIViewController


@property ToDoItem *toDoItem;
@property NSString *itemName;
@property BOOL completed;
@property (readonly) NSDate *creationDate;

@end