objective-c - 类 超类 子类

Question

我正在尝试使两个子类成为一个类：

// Old code

- (void)setPaging {
    [pagingScrollView addSubview:self.ImageScrollView];
}

@interface ImageScrollView : UIScrollView <UIScrollViewDelegate> {
    UIView        *imageView;
    NSUInteger     index;
}
@property (assign) NSUInteger index;
- (void)displayTiledImageNamed:(CGPDFPageRef)page size:(CGSize)imageSize;
@end

@implementation ImageScrollView
@synthesize index;
// ... my methods ...
@end

变成：

// NEW Code__________________________________________________________*

- (void)setPaging {
    if (D == 1) {
        // error: request for member 'ISVportrate' in something not a
        // structure or union
        [pagingScrollView addSubview:self.ISVportrate];
    } else if (D == 2) {
        //error: request for member 'ISVLandscape' in something not a
        // structure or union
        [pagingScrollView addSubview:self.ISVLandscape];
    }
}

@class ISVportrate;
@class ISVLandscape;
@interface ImageScrollView : UIScrollView <UIScrollViewDelegate> {
    UIView        *imageView;
    NSUInteger     index;
}
@property (assign) NSUInteger index;
- (void)displayTiledImageNamed:(CGPDFPageRef)page size:(CGSize)imageSize;
@end
@interface ISVportrate : ImageScrollView {}
@end
@interface ISVLandscape : ImageScrollView {}
@end

@implementation ISVportrate : ImageScrollView

// error: property 'index' attempting to use ivar 'index' declared in
// super class of 'ISVportrate'
@synthesize index;

// ... my methods ...
@end
@implementation ISVLandscape : ImageScrollView

// error: property 'index' attempting to use ivar 'index' declared in
// super class of 'ISVLandscape'
@synthesize index;

// ... my methods ...
@end

我这样做不对，是吗？见上面我有4个错误……这是我第一次上课……帮助我理解，我想我几乎做对了。

Answer 1

在@synthesizeof@implementation中ImageScrollView，不在子类中。

self.ISVportrate没有意义（除非你有一个名为 的方法-ISVportrate，这也没有意义）。

听起来您还没有完全了解面向对象的编程。您可能希望创建一个子类的适当实例，并将其分配为包含它的任何视图的子视图......