Question

我使用nsnumber作为计数器，但它没有保留其值。它可能是一个指针问题，因为它在我的init语句中显示为13但在我的tap中显示为null。我不确定这是怎么回事。我从来没有真正搞过我的属性自动生成的_instanceValue。我一直使用self.propertyName作为访问者。我相信这可能与它有关。

头文件

@interface PezStoryViewer : UIViewController


@property(nonatomic, strong) NSNumber *counter;


-(id)initWithScene:(NSArray *)scenes;
+(void)viewTapped:(UIGestureRecognizer *)gesture;
+ (id)sharedInstance;

@end

m file

-(id)initWithScene:(NSArray *)scenes{

self = [super init];

if (self) {

    //reverse array order
    scenes = [[scenes reverseObjectEnumerator] allObjects];

    //set counter
    _counter = [[NSNumber alloc] initWithUnsignedInteger:[scenes count]];
    NSLog(@"_counter = %@", _counter);

    //initialize subviews
    //and other stuff
    }


 return self;

}



-(void)viewTapped:(UIGestureRecognizer *)gesture{

NSLog(@"tap");

NSLog(@"_counter = %@", _counter);
NSUInteger i = [_counter unsignedIntegerValue];
i--;
NSLog(@"counter = %d", i);


if ([gesture.view isKindOfClass:[PezFrontImageView class]]) {
    //3 Steps
    //1: pop off subview
    [gesture.view removeFromSuperview];
    //2: if next view is a video, play it
    //3: initialize new frontView under the existing backView
}


if (i==7) {
    [self dismissViewControllerAnimated:NO completion:nil];
}

_counter = [NSNumber numberWithUnsignedInt:i];


}

+ (id)sharedInstance {
static id sharedInstance;
@synchronized(self) {
    if (!sharedInstance)
        sharedInstance = [[PezStoryViewer alloc] init];
    return sharedInstance;
}
}

点击我的子视图中的UIImageView自定义类

类型的手势

    //add tapGesture
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:[PezStoryViewer sharedInstance] action:@selector(viewTapped:)];
    [self addGestureRecognizer:tapGesture];

Answer 1

请注意，您的sharedInstance方法不会致电initWithScene:。它只是调用init。所以你永远不会初始化counter属性。

您真的不应该将视图控制器设置为单例。只需在需要时创建视图控制器并使用initWithScene:方法。

NSNumber实例不会保留值

1 个答案: