objective-c - No Visible @interface for 'GameViewController' 声明选择器 'createCardTypeDeck'

Question

我在这些代码行上遇到错误。谢谢

This is the first line of code
[ar exchangeObjectAtIndex:i withObjectAtIndex:n];

这是我得到的错误

use of undeclared identifier 'ar'

下一段代码

-(NSMutableArray*)createCardTypeDeck: {

这是我得到的错误

expected identifier  

这是下一个

-(void)updateCard: (UIButton*) card, cardType: (int) cardType (

这是错误

Expected method body 

这是最后一个

@end

这是一个奇怪的错误

Missing '@end'

感谢大家的帮助如果您还没有 guest ，我是编码新手。

#import "GameViewController.h"

@interface GameViewController () 

@end

@interface NSArray(Shuffle)
-(NSArray *)shuffledArray;
@end

@implementation GameViewController
-(void)shuffleArray: (NSMutableArray*)arr {
    NSUInteger count = [arr count];
    for (NSUInteger i = 0; i < count; ++i) {
        // Select a random element between i and end of array to swap with.
        int nElements = count - i;
        int n = (arc4random() % nElements) + i;
        [ar exchangeObjectAtIndex:i withObjectAtIndex:n];  //this is where I get the first error.)
    }
}

-(NSMutableArray*)createCardTypeDeck: {     //This is the second one.
    NSMutableArray *cardTypes = [NSMutableArray arrayWithCapacity:8];
    for (int i = 0; i < 4; i++) {
        // Add the same number twice, for a total 8 objects added
        [cardTypes addObject:[NSNumber numberWithInteger:i]];
        [cardTypes addObject:[NSNumber numberWithInteger:i]];
    }
    return cardTypes;
}

// Take in /a/ card and the type, so it will work for all cards;
// don't add the card to the view here. Note there is no hard-coding of
// card1..card8 and thus there is NO NEED to duplicate this method 8 times!
-(void)updateCard: (UIButton*) card, cardType: (int) cardType (    (The third error.)
{
    // The imageName and UIImage creation could be further extracted but
    // this should be sufficient to show how much common code (and copy'n'paste)
    // can be eliminated - resulting in shorter and more readable code.
    NSString *imageName;
    switch (cardType) {
        case 0:
            imageName = @"cell phone.jpeg";
            break;
        case 1:
            imageName = @"Dinasore.jpeg";
            break;
        case 2:
            imageName = @"jump Rope.jpeg";
            break;
        case 3:
            imageName = @"monkey.jpeg";
            break;

        default:
            image = nil; // but really an error of some sort
            break;
    }
    UIImage *image = [UIImage imageNamed:imageName];
    [card setImage:image forState:UIControlStateNormal];
}
- (void)viewDidLoad
{
    {
        // Create card/cardType deck, values   -> [0, 0, 1, 1, 2, 2, 3, 3]
        NSMutableArray *cardTypes = [self createCardTypeDeck];
        // Shuffle the card types, result e.g. -> [2, 1, 0, 3, 2, 3, 0, 1]
        [self shuffleArray: cardTypes];

        // At least we only use the names once now
        NSArray *cards = [NSArray arrayWithObjects:
                          card1, card2, card3, card4,
                          card5, card6, card7, card8, nil];

        // For each card, assign it an image and otherwise finish adding it
        for (int i = 0; i < 8; i++) {
            // Get now shuffled cardType and this index
            // (We know that only values 0..3 will appear and each will appear
            //  exactly twice - as only those values, and that multiplicity,
            //  have been added to the original array before shuffling.)
            int cardType = [[cardTypes objectAtIndex:i] intValue];
            // Get the card to apply the changes to, and do so
            UIButton* card = [cards objectAtIndex:i];
            [self updateCard:card withType:cardType];
            // Then add the card view
            [self.view addSubview:card];
        }











    card1Selected.hidden = YES;
    card2Selected.hidden = YES;
    card3Selected.hidden = YES;
    card4Selected.hidden = YES;
    card5Selected.hidden = YES;
    card6Selected.hidden = YES;
    card7Selected.hidden = YES;
    card8Selected.hidden = YES;

    card1Type = arc4random() %4;
    card2Type = arc4random() %4;
    card3Type = arc4random() %4;
    card4Type = arc4random() %4;
    card6Type = arc4random() %4;
    card7Type = arc4random() %4;
    card8Type = arc4random() %4;


    [self Card1SelectedType];
    [self Card2SelectedType];
    [self Card3SelectedType];
    [self Card4SelectedType];
    [self Card5SelcetedType];
    [self Card6SelectedType];
    [self Card7SelectedType];
    [self Card8SelectedType];







    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
@end   //and this is the last error

Answer 1

首先，当您调用 [ar exchangeObjectAtIndex:i withObjectAtIndex:n]; 时，您会收到该错误，这意味着编译器不知道不存在名为“ar”的变量。您是否在任何时候创建了名为“ar”的变量？

其次，创建不带参数的函数的方式如下:

- (NSMutableArray*)createCardTypeDeck {

}

或者，如果您确实希望它接受一个参数，例如 NSString，您可以这样做:

- (NSMutableArray*)createCardTypeDeck:(NSString *)someString {

}

createCardTypeDeck 之后有“:”，但没有提供参数，因此要么像上面那样定义一个参数，要么删除 :。

第三，你的 updateCard 方法有一个 ( 而不是 { 作为方法主体，它应该是这样的:

- (void)updateCard: (UIButton*) card, cardType: (int) cardType {

}

解决这个问题也应该可以解决您的@end问题。