'卡'可能不會響應'-fadeAway'

Question

我有一個Card類從UIView和從NSObject Deck類分類。 Card在繼承的UIView之上有幾個整數屬性，Deck有一個用於存放一些卡的NSMutableArray。生成一副牌後，我想顯示一張隨機選擇的牌（通過將其添加到超級視圖中）。在我做之前，我會檢查是否已經有一張卡片，我打電話給方法在請求一張新卡片之前將其釋放。但是我在標題中得到了警告。下面的代碼...

---

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

@interface FlashTestViewController : UIViewController { 

Deck*  aDeck; 
Card*  aCard; 
} 

- (IBAction)generateDeck; 
- (IBAction)generateCard; 
- (void)fadeAway:(id)sender; 

@end 

---

#import "FlashTestViewController.h" 

@implementation FlashTestViewController 

- (IBAction)generateDeck { 

    if (aDeck != nil) { 
     [aDeck release]; 
    } 

    aDeck = [[Deck alloc] initDeckWithOperator:@"+"]; 
} 


- (IBAction)generateCard { 

    if (aCard != nil) { 
     [aCard fadeAway]; 
    } 

    aCard = [aDeck newCardFromDeck]; 
    [self.view addSubview:aCard]; 
} 

- (void)fadeAway:(id)sender { 
    [aCard removeFromSuperview]; 
    [aCard release]; 
    } 

---

我在編程初學者（比其他基礎！），所以我仍然包裹我的頭圍繞整個對象的事。感謝您的任何幫助和/或建議！

編輯： 這裏的卡和甲板代碼...

---

#import <UIKit/UIKit.h> 
#import <QuartzCore/QuartzCore.h> 

@class Card; 

@interface Card : UIView { 

int   upperOperand; 
int   lowerOperand; 
NSString* theOperator; 
int   theResult; 
} 

@property(nonatomic) int upperOperand; 
@property(nonatomic) int lowerOperand; 
@property(nonatomic, retain) NSString* theOperator; 
@property(nonatomic) int theResult; 

@end 

---

#import "Card.h" 


@implementation Card 

@synthesize upperOperand; 
@synthesize lowerOperand; 
@synthesize theOperator; 
@synthesize theResult; 

- (id)initWithFrame:(CGRect)frame { 
    if ((self = [super initWithFrame:frame])) { 
    // Initialization code 
    self.backgroundColor = [UIColor redColor]; 
    self.layer.cornerRadius = 15; 
    self.alpha = 0.3; 
    self.layer.borderColor = [[UIColor blueColor] CGColor]; 
    self.layer.borderWidth = 4; 
    } 
    return self; 
} 

- (void)dealloc { 
    [super dealloc]; 
} 

@end 

---

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

@class Deck; 

@interface Deck : NSObject { 

NSMutableArray* cards; 
} 

@property(nonatomic, retain) NSMutableArray* cards; 

- (id)initDeckWithOperator: (NSString*)mathOper; 
- (id)newCardFromDeck; 

@end 

---

#import "Deck.h" 

@implementation Deck 

@synthesize cards; 

- (id)initDeckWithOperator: (NSString*)mathOper { 
    if (cards != nil) { 
    [cards release]; 
    } 
    cards = [[NSMutableArray alloc] init]; 
    for (int i=0; i<11; i++) { 
     for (int j=0; j<11; j++) { 
      Card* aCard = [[Card alloc] initWithFrame:CGRectMake(10, 10, 60, 80)]; 
      aCard.upperOperand = i; 
      aCard.lowerOperand = j; 
      aCard.theOperator = mathOper; 
      aCard.theResult = i + j; 
      [cards addObject: aCard]; 
      [aCard release]; 
     } 
    } 
    return self; 
} 

- (id)newCardFromDeck { 
    int index = random() % [cards count]; 
    Card* selectedCard = [[cards objectAtIndex:index] retain]; 
    [cards removeObjectAtIndex:index]; 
    return selectedCard; 
} 

@end 

Answer 1

您已經定義爲FlashTestViewController類，而不是Card類fadeAway方法。這意味着您只能在Card類的實例上調用此方法（或根據您的首選OOP術語發送消息）。

所以[aCard fadeAway]不正確，因爲它需要錯號碼則params的，也因爲ACARD是Card類實例和fadeAway:方法沒有爲該類定義（當然，我們並沒有看到它的定義，所以也許它是但不是如此）。

但是您沒有顯示Card類的定義，因此您可能會在那裏定義方法。

Answer 2

您需要爲aCard提供一個(id)sender，如您在參數中所述。你沒有給出足夠的論據來換句話說。

Answer 3

您將fadeAway聲明爲採用id類型的單個參數，因此您必須這樣調用它。所以：

[aCard fadeAway:nil]; 

而且，因爲它從來不與它的參數任何東西，你可以簡單地聲明它不會採取一個，然後把它原樣。所以：

-(void)fadeAway; 

// later 
[aCard fadeAway];