如何訪問作為對象實例屬性的可變數組並使用值填充該數組

Question

我有一個Card Object，它有4個實例變量，即name（NSString），pin（NSString），points（NSNumber），pointsToDeduct（NSMutableArray）。

卡h

@interface Card : NSObject

    @property (nonatomic, strong) NSString *name;
    @property (nonatomic, strong) NSString *pin;
    @property (nonatomic, strong) NSNumber *points;
    @property (nonatomic, strong) NSMutableArray *pointsToDeduct;

@end

我制作的Card的每個新實例始終存在pointsToDeduct數組。 我想要的是用另一個數組的值（通過單擊按鈕是靜態的）填充它的值。 但是在此之前，在下面的代碼中，我將這些靜態值轉換為NSNumber，以便pointsToDeduct的值將為NSNumber類型。 我正在考慮委托這樣做，盡管不確定是否最好。 現在，我想訪問pointsToDeduct數組，以便可以在其中添加值。

*這是PerksDetailsViewController.m的一部分

- (IBAction)redeemPressed:(id)sender {

     NSNumber *pointsRequired;
     NSNumberFormatter * formatter = [[NSNumberFormatter alloc] init];
     [formatter setNumberStyle:NSNumberFormatterDecimalStyle];

     pointsRequired = [formatter numberFromString: (self.pointsLabel.text)];

     NSLog(@"points required by the perk %@", pointsRequired);

    // now insert pointsRequired's value to pointsToDeduct array instance variable of a Card

以下是我擁有的其他代碼。

主視圖CardWalletViewController.h

#import <UIKit/UIKit.h>

@interface CardWalletViewController : UITableViewController 

@property (nonatomic, strong) NSMutableArray *myWallet;

-(void) printArrayContents;

CardWalletViewController.m

#import "CardWalletViewController.h"
#import "AddCardViewController.h"
#import "Card.h"
#import "CardDetailsViewController.h"

@interface CardWalletViewController () <AddCardDelegate>

@end

@implementation CardWalletViewController


@synthesize myWallet = _myWallet;

- (NSMutableArray *) myWallet
{
    if (_myWallet == nil) _myWallet = [[NSMutableArray alloc] init]; 
    return _myWallet;
}


- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"showAddCardVC"]) {
        AddCardViewController *addCardVC = (AddCardViewController *)segue.destinationViewController;

        addCardVC.delegate = self;

    }
}

- (void)printArrayContents 
{

    // I want to show the name of each instance

    for ( int i = 0; i < self.myWallet.count; i++) {
        Card *cardDummy = [self.myWallet objectAtIndex:i];
        NSLog(@"Element %i is %@", i,cardDummy.name );
    }
}

- (void)addCardViewController:(AddCardViewController *)sender didCreateCard:(Card *)newCard
{
    // insert a new card to the array

    [self.myWallet addObject:newCard];

    [self printArrayContents];
    [self.tableView reloadData];
}

- (void)saveMyWallet: (NSMutableArray *)myWallet
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    [defaults setObject:self.myWallet forKey:@"myWalletArray"];

    [defaults synchronize];
    NSLog(@"I am saved");
}


- (NSMutableArray *)loadWallet 
 {
    NSMutableArray *boom;
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    boom = [defaults objectForKey: @"myWalletArray"];

    if (!boom) {
        boom = [[NSMutableArray alloc] init];
    }



 return boom;

}

- (void)viewDidLoad
{
    [self loadWallet];
    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.
}

- (void)viewDidUnload
{
    [super viewDidUnload];

    // Release any retained subviews of the main view.
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    //this method will return the number of rows to be shown
    return self.myWallet.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];

    }


    Card *cardDummy = [self.myWallet objectAtIndex:indexPath.row];
    cell.textLabel.text = cardDummy.name;
    cell.detailTextLabel.text = [NSString stringWithFormat:@"%@", cardDummy.points]; 

    return cell;
}

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

    //this method is responsible for showing the details of a selected card
    //make another view controller - DetailVC perhaps

    CardDetailsViewController *details = [self.storyboard instantiateViewControllerWithIdentifier:@"cardDetails"];


    Card *cardDummy = [self.myWallet objectAtIndex:indexPath.row];

    details.myPoints = [NSString stringWithFormat:@"%@", cardDummy.points];

    [self.navigationController pushViewController:details animated:YES];
}



- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 60;
}


- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

@end

我創建新卡的方式

AddCardViewController.m

#import "AddCardViewController.h"
#import "Card.h"
#import "CardWalletViewController.h"

@interface AddCardViewController ()

@end

@implementation AddCardViewController 

@synthesize cardNameTextField = _cardNameTextField;
@synthesize pinTextField = _pinTextField;
@synthesize pointsTextField = _pointsTextField;

@synthesize delegate = _delegate;


- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self.cardNameTextField becomeFirstResponder];


}    

- (BOOL) textFieldShouldReturn:(UITextField *)textField{

    if ([textField.text length]) {
    [self.cardNameTextField resignFirstResponder];

    [self.pinTextField resignFirstResponder];

    [self.pointsTextField resignFirstResponder];

    return YES;
    }

    else {
        return NO;
    }
}

- (void)viewDidLoad
{
    self.cardNameTextField.delegate = self;
    self.pinTextField.delegate = self;
    self.pointsTextField.delegate = self;
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)viewDidUnload
{
    [self setCardNameTextField:nil];
    [self setPinTextField:nil];
    [self setPointsTextField:nil];
    [super viewDidUnload];
    // Release any retained subviews of the main view.
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

- (IBAction)addCard:(id)sender 
{
    Card *myNewCard = [[Card alloc] init];


    myNewCard.name = self.cardNameTextField.text;

    myNewCard.pin = self.pinTextField.text;


    NSNumber *myPoints;
    NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
    [f setNumberStyle:NSNumberFormatterDecimalStyle];

    myPoints = [f numberFromString: (self.pointsTextField.text)];

    myNewCard.points = myPoints;


    //method here that will dismiss the modal view
    // if condition forces the user to fill up all the text field

    if ([self.cardNameTextField.text length] && [self.pinTextField.text length] && [self.pointsTextField.text length]) 
    {
        //method here that will dismiss the modal view
        [[self presentingViewController] dismissModalViewControllerAnimated:YES];


        //checking...
        NSLog(@"name saved %@", myNewCard.name);
        NSLog(@"pin saved %@", myNewCard.pin);
        NSLog(@"points saved %@", myNewCard.points);

        [self.delegate addCardViewController:self didCreateCard:myNewCard];

        // to check if there is a delegate
        /*
         if (self.delegate){
            NSLog(@"delegate is not nil");
        }
         */
    }
}

@end

AddCardViewController.h

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

@class AddCardViewController;

@protocol AddCardDelegate <NSObject>

- (void)addCardViewController:(AddCardViewController *)sender
                didCreateCard:(Card *) newCard;

@end


@interface AddCardViewController : UIViewController <UITextFieldDelegate>


@property (strong, nonatomic) IBOutlet UITextField *cardNameTextField;
@property (strong, nonatomic) IBOutlet UITextField *pinTextField;
@property (strong, nonatomic) IBOutlet UITextField *pointsTextField;

@property (nonatomic, strong) id <AddCardDelegate> delegate;

@end

CardDetailsViewController.m

#import "CardDetailsViewController.h"
#import "PerksDetailsViewController.h"
#import "Card.h"

@interface CardDetailsViewController ()

@end

@implementation CardDetailsViewController

@synthesize pointsLabel = _pointsLabel;
@synthesize myPoints  = _myPoints;

@synthesize perks = _perks;
@synthesize datasource = _datasource;
@synthesize datasourcePoints = _datasourcePoints;

-(void)setupArray
{
    self.perks = [[NSMutableDictionary alloc] init];
    [self.perks setObject:@"200" forKey:@"10% Discount"];
    [self.perks setObject:@"100" forKey:@"250Php Off"];

    self.datasource = [self.perks allKeys]; //contains perk's description
    self.datasourcePoints = [self.perks allValues]; //contains perk's required points
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{
    return 2;
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
    }

    cell.textLabel.text = [self.datasource objectAtIndex:indexPath.row];
    cell.detailTextLabel.text = [self.datasourcePoints objectAtIndex:indexPath.row];

    return cell;
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    PerksDetailsViewController *perksDetails = [self.storyboard instantiateViewControllerWithIdentifier:@"detailsOfMyPerks"];
    [self.navigationController pushViewController:perksDetails animated:YES];

    perksDetails.perkDetailsLabel.text = [self.datasource objectAtIndex:indexPath.row];
    perksDetails.pointsLabel.text = [self.perks objectForKey:perksDetails.perkDetailsLabel.text];
}


- (void)viewDidLoad
{

    //show the number of points of the selected Card

    self.pointsLabel.text = self.myPoints;
    self.navigationItem.title = @"Your Points";

    [self setupArray];
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)viewDidUnload
{
    [self setPointsLabel:nil];
    [super viewDidUnload];
    // Release any retained subviews of the main view.
}

@end

CardDetailsViewController.h

#import <UIKit/UIKit.h>

@interface CardDetailsViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> 
{

}

@property (nonatomic, retain) NSMutableDictionary *perks;
@property (nonatomic, retain) NSArray *datasource;
@property (nonatomic, retain) NSArray *datasourcePoints;

-(void)setupArray;

@property (strong, nonatomic) IBOutlet UILabel *pointsLabel;
@property (nonatomic, weak) NSString *myPoints;

@end

PerksDetailsViewController.m

#import "PerksDetailsViewController.h"
#import "Card.h"
#import "CardWalletViewController.h"

@interface PerksDetailsViewController ()

@end

@implementation PerksDetailsViewController

@synthesize pointsLabel = _pointsLabel;
@synthesize perkDetailsLabel = _perkDetailsLabel;
@synthesize perkDetailText = _perkDetailText;
@synthesize pointsText = _pointsText;

- (IBAction)redeemPressed:(id)sender {
    // get required points of a perk selected
    // cast the NSString value to an int/NSInteger

     NSNumber *pointsRequired;
     NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
     [f setNumberStyle:NSNumberFormatterDecimalStyle];

     pointsRequired = [f numberFromString: (self.pointsLabel.text)];

    NSLog(@"points required by the perk %@", pointsRequired);

    // now insert this value to points array instance variable of a Card        

}



- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    //self.perkDetailsLabel.text = self.perkDetailText;
    //self.pointsLabel.text = self.pointsText;
    NSLog(@"perk detail:%@", self.perkDetailText);
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)viewDidUnload
{
    [self setPerkDetailsLabel:nil];
    [self setPointsLabel:nil];
    [super viewDidUnload];
    // Release any retained subviews of the main view.
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

@end

PerksDetailsViewController.h

#import <UIKit/UIKit.h>

@interface PerksDetailsViewController : UIViewController
{
    NSString *perkDetailText;
    NSString *pointsText;
    IBOutlet UILabel *perkDetailsLabel;
    IBOutlet UILabel *pointsLabel;
}

@property (nonatomic, retain) IBOutlet UILabel *perkDetailsLabel, *pointsLabel;

@property (nonatomic, retain) NSString *perkDetailText, *pointsText;

@end

Answer 1

當前類中的NSMutable數組從iPhone中的一個類轉移到另一個類

#import "SecondViewController"
 SecondViewController *NextViewController = [[SecondViewController alloc]initWithNibName:@"SecondViewController" bundle:nil];

        NextViewController.nextClasssArray = thisClassarray;

在第二課.h

@property(nonatomic,retain) NSMutableArray *nextClasssArray;
in second class .m

@synthesize nextClasssArray;

Answer 2

您的PerksDetailViewController需要具有當前Card對象的屬性。 然后，這只是一個問題

[self.card.pointsToDeduct addObject:pointsRequired];

在您的所有示例代碼中，我看不到您實際上在使用任何Card對象的位置。