我关心我的 4 个视图控制器。第一个是 CardWalletViewController，它是一个表格视图，由用户创建的卡片对象填充（卡片创建是可以的，所以我不会发布有关的代码）。现在，鉴于这个表格视图已经填充了卡片对象，一旦用户点击一个单元格，另一个名为 CardDetailsViewController 的视图控制器就会出现。这将显示卡的当前积分以及特权。请注意，当前点通过 UILabel 显示，并且特权是表格视图的单元格。此表视图的单元格值（特权）是静态类型的，来自 NSDictionary，然后存储在 NSArray 中（用于单元格的文本显示目的）。现在，当我点击一个福利时，PerksDetailsViewController 会出现。这包含显示 perk 名称和所需点数的 UILabels。这些 UILabels 值来自以前的 ViewController。此外，PerksDetailsVC 有一个名为兑换的按钮。单击该按钮后，我将进入另一个视图控制器 BarCodeViewController，它负责计算。
现在我关心的是如何通过选定的卡片，以及与选定的特权相对应的点数。我已经使用委托来执行此操作，但似乎我的委托对象没有被设置。
以下是我当前的代码。
CardWalletViewController.h
#import <UIKit/UIKit.h>
#import "Card.h"
@class CardWalletViewController;
@protocol CardWalletDelegate <NSObject>
-(void)cardWalletViewController: (CardWalletViewController *)sender
withCurrentCard: (Card *) currentCard;
@end
@interface CardWalletViewController : UITableViewController
@property (nonatomic, strong) NSMutableArray *myWallet;
@property (nonatomic, weak) id <CardWalletDelegate> delegate;
@end
CardWalletViewController.m
#import "CardWalletViewController.h"
#import "AddCardViewController.h"
#import "Card.h"
#import "CardDetailsViewController.h"
@interface CardWalletViewController ()
@end
@implementation CardWalletViewController
@synthesize delegate = _delegate;
- (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]; //myWallet is an Array where the table cell's values come from
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
CardDetailsViewController *details = [self.storyboard instantiateViewControllerWithIdentifier:@"cardDetails"];
Card *selectedCard = [self.myWallet objectAtIndex:indexPath.row]; // I want this selected card to be accessible until the user clicks another card or during end of program.
details.myPoints = [NSString stringWithFormat:@"%@", selectedCard.points];
[self.navigationController pushViewController:details animated:YES];
[self.delegate cardWalletViewController:self withCurrentCard:selectedCard];
//checking purposes
if (!self.delegate) {
NSLog(@"delegate is nil");
}
}
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 setupArray];
[super viewDidLoad];
}
PerksDetailsViewController.m
#import "PerksDetailsViewController.h"
#import "Card.h"
#import "CardWalletViewController.h"
#import "BarcodeViewController.h"
@interface PerksDetailsViewController ()
@end
@implementation PerksDetailsViewController
@synthesize pointsLabel = _pointsLabel;
@synthesize perkDetailsLabel = _perkDetailsLabel;
@synthesize perkDetailText = _perkDetailText;
@synthesize pointsText = _pointsText;
@synthesize delegate = _delegate;
@synthesize pointsRequired = _pointsRequired;
- (IBAction)redeemPressed:(id)sender {
// get required points of a perk selected
// cast the NSString value to an NSInteger
NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterDecimalStyle];
self.pointsRequired = [f numberFromString: (self.pointsLabel.text)];
NSLog(@"points required by the perk %@", self.pointsRequired);
[self.delegate perksDetailsViewController:self didPassRequiredPoints:self.pointsRequired];
if (!self.delegate){
NSLog(@"delegate is nil");
}
}
PerksDetailsViewController.h
#import <UIKit/UIKit.h>
#import "BarcodeViewController.h"
@class PerksDetailsViewController;
@protocol PerksDetailsDelegate <NSObject>
- (void)perksDetailsViewController:(PerksDetailsViewController *)sender
didPassRequiredPoints: (NSNumber *) requiredPoints;
@end
@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;
@property (nonatomic, weak) NSNumber *pointsRequired;
@property (nonatomic, weak) id <PerksDetailsDelegate> delegate;
@end
现在这个 ViewController 是实现两个委托方法的那个
条码视图控制器.h
#import <UIKit/UIKit.h>
@interface BarcodeViewController : UIViewController
@property (nonatomic, strong) NSNumber *myPoints;
@end
条码视图控制器.m
#import "BarcodeViewController.h"
#import "CardWalletViewController.h"
#import "Card.h"
#import "PerksDetailsViewController.h"
@interface BarcodeViewController () <CardWalletDelegate, PerksDetailsDelegate>
@end
@implementation BarcodeViewController
@synthesize myPoints = _myPoints;
- (void)perksDetailsViewController:(PerksDetailsViewController *)sender didPassRequiredPoints:(NSNumber *)requiredPoints
{
self.myPoints = requiredPoints;
}
- (void)cardWalletViewController:(CardWalletViewController *)sender withCurrentCard:(Card *)currentCard
{
Card *myCurrentCard = currentCard;
[myCurrentCard.pointsToDeduct addObject:self.myPoints];
NSLog(@"contents :%@", [myCurrentCard.pointsToDeduct description]);
}
@end