我有一个视图以编程方式加载为子视图。该视图在.h中定义了三个属性,并在.m中进行了合成。该视图是通过在父控制器中创建视图的对象并随后调用它的初始化函数来加载的。在初始化函数中,我为它们各自的属性设置了许多值。出于某种原因,我无法访问初始化函数之外的属性。我的第一个想法是,这些属性的定义不正确,但是在弄乱它们的强弱属性之后,没有任何变化。IOS问题访问类属性
了UIView的.H
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
#import <Parse/Parse.h>
@protocol subViewDelegate
- (void)photoFromSubview:(NSInteger *)imageId;
- (void)downloadData;
@end
@interface ImageViewer : UIView
@property (nonatomic, assign) id <subViewDelegate> delegate;
//three properties
@property (nonatomic, copy) UIImage *mainImage;
@property (nonatomic, copy) UIViewController *parentView;
@property (nonatomic) NSInteger imageId;
- (void)removeImageViewer;
- (void)captureImage:(id)sender;
- (void)uploadPhoto:(id)sender;
- (UIImage *)addBackground;
- (ImageViewer *)loadImageIntoViewer:(UIViewController *)superView imageToLoad:(UIImage *)imageToLoad imageId:(NSInteger *)imageId;
@end
在UIViews相关职能.M
//implementation of the properties
#import "ImageViewer.h"
#import "SpinnerView.h"
@implementation ImageViewer : UIView
{
}
@synthesize mainImage = _mainImage;
@synthesize parentView = _parentView;
@synthesize imageId = _imageId;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
}
return self;
}
//initialization function
- (ImageViewer *)loadImageIntoViewer:(UIViewController *)superView imageToLoad:(UIImage *)imageToLoad imageId:(NSInteger *)imageId
{
//create a new view with the same frame size as the superView
ImageViewer *imageViewer = [[ImageViewer alloc] initWithFrame:superView.view.bounds];
imageViewer.delegate = superView;
//three properties assigning values
_mainImage = imageToLoad;
_parentView = superView;
_imageId = imageId;
//if something's gone wrong, abort!
if(!imageViewer)
{
return nil;
}
//add all components and functionalities to the program
//when I use _mainImage bellow it works with the correct value
UIImageView *background = [[UIImageView alloc] initWithImage:[imageViewer addBackground]];
background.alpha = 0.85;
[imageViewer addSubview:background];
[imageViewer addSubview:[imageViewer addImageToView:_mainImage superView:superView.view]];
[imageViewer addSubview:[imageViewer addButtonToView:(superView.view.bounds.origin.x + 10.0) yPos:(superView.view.bounds.origin.x + 10.0) buttonAction:@selector(back:) buttonTitle:@"Back"]];
[imageViewer addSubview:[imageViewer addButtonToView:(superView.view.bounds.origin.x + 10.0) yPos:((superView.view.center.y/2) + 270.0) buttonAction:@selector(captureImage:) buttonTitle:@"Camera"]];
[imageViewer addSubview:[imageViewer addButtonToView:(superView.view.bounds.origin.x + 105.0) yPos:((superView.view.center.y/2) + 270.0) buttonAction:@selector(uploadPhoto:) buttonTitle:@"Upload"]];
[superView.view addSubview:imageViewer];
return imageViewer;
}
上面的代码可以访问分配给_mainImage,_parentView和_imageId值。但是,当我尝试通过.m中定义的私有函数访问它们时,返回初始化值,如下所示。
- (void)uploadPhoto:(id)sender
{
//These all return as empty or uninitialized
NSLog(@"%@", _mainImage);
NSLog(@"%d", _imageId);
}
这是为什么?我在.h中错误地定义了属性还是因为self没有引用在loadImageIntoViewer中定义的ImageView实例?我怎样才能解决这个问题?
一个问题,如果你宣布他们强大而不是复制它的私人方法工作? – Radu 2013-05-09 14:16:33
我相信你不想要UIViewController的副本 - 你想要一个弱引用。 – 2013-05-09 14:21:38