Question

我有一个IKImageBrowserView，它有自己的控制器 - BrowserController.h + .m

@interface BrowserController : NSWindowController{
    NSMutableArray *_images;
}
@property (strong,nonatomic) IBOutlet IKImageBrowserView *imageBrowser;

-(void)addMultipleImages;

当我第一次运行应用程序时，会加载凝视图像，但是当我单击按钮添加其他图像并从另一个类调用方法时，我没有得到任何结果。我注意到我的_imageBrowser丢失了引用并变为nil。

我该如何解决这个问题？

AppDelegate.m

#import "AppDelegate.h"
#import "BrowserController.h"

@implementation AppDelegate{
    BrowserController *imageBrowserController;
}

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    // Insert code here to initialize your application
    imageBrowserController = [BrowserController sharedManager];

}

- (IBAction)doSomething:(id)sender {
    [imageBrowserController addMultipleImages];
}


@end

BrowserController.m

#import "BrowserController.h"
@interface myImageObject : NSObject
{
    NSString *_path;
}
@end


@implementation myImageObject

/* our datasource object is just a filepath representation */
- (void)setPath:(NSString *)path
{
    if(_path != path)
    {
        _path = path;
    }
}

/* required methods of the IKImageBrowserItem protocol */
#pragma mark -
#pragma mark item data source protocol

/* let the image browser knows we use a path representation */
- (NSString *)imageRepresentationType
{
    return IKImageBrowserPathRepresentationType;
}

/* give our representation to the image browser */
- (id)imageRepresentation
{
    return _path;
}

/* use the absolute filepath as identifier */
- (NSString *)imageUID
{
    return _path;
}

@end


@interface BrowserController ()

@end

@implementation BrowserController

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code here.
    }
    return self;
}

- (void)drawRect:(NSRect)dirtyRect
{
    [super drawRect:dirtyRect];

    // Drawing code here.
}

- (void)awakeFromNib{

    myImageObject *p;
    p = [[myImageObject alloc]init];
    [p setPath:[[NSBundle mainBundle]pathForResource:@"Unknown" ofType:@"jpg"]];
    _images = [[NSMutableArray alloc]init];
    [_images addObject:p];

    [self updateDataSource];
}


- (void)updateDataSource{

    [_imageBrowser reloadData];
}

-(NSUInteger) numberOfItemsInImageBrowser:(IKImageBrowserView *)aBrowser{
    return [_images count];
};

-(id)imageBrowser:(IKImageBrowserView *)aBrowser itemAtIndex:(NSUInteger)index{
    return [_images objectAtIndex:index];
};

- (void)updateDatasource
{
    [_imageBrowser reloadData];
}

- (void)addMultipleImages{
    myImageObject *p;
    p = [[myImageObject alloc]init];
    [p setPath:[[NSBundle mainBundle]pathForResource:@"Unknown" ofType:@"jpg"]];
    _images = [[NSMutableArray alloc]init];
    [_images addObject:p];
    [_images addObject:p];
    [_images addObject:p];

    [_imageBrowser reloadData];
}


+ (id)sharedManager {
    static BrowserController *sharedMyManager = nil;
    @synchronized(self) {
        if (sharedMyManager == nil)
            sharedMyManager = [[self alloc] init];
    }
    return sharedMyManager;
}


@end

Answer 1

_{在你问题的开头提到它的类的名称ImageBrowserController有一些混淆，看起来在你的问题结束时它被称为BrowserController}

问题是您在_images中分配awakeFromNib，因为该类是通过单例模式（sharedInstance创建的）而不是从.nib加载的，所以永远不会调用awakeFromNib文件。

因此，请将代码从init移至awakeFromNib并转储- (id)init { self = [super init]; if (self) { myImageObject *p = [[myImageObject alloc]init]; [p setPath:[[NSBundle mainBundle]pathForResource:@"Unknown" ofType:@"jpg"]]; _images = [[NSMutableArray alloc]init]; [_images addObject:p]; [self updateDataSource]; } return self; }：

BrowserController.m：

initWithFrame

进一步混淆：您已实施{{1}}方法。为什么呢？

对象失去参考

1 个答案: