关于init和load from xib for custom UIView的问题

Question

我正在尝试创建一个自定义UIView类，它从包含该视图接口的xim文件加载。我试图封装[NSBundle mainBundle] loadNibNamed…在我的自定义视图的init方法中，如下所示:

- (id)init 
{    
    self = [super init];
    if (self) 
    {
        NSArray* nibViews = [[NSBundle mainBundle] loadNibNamed:@"LoadingV" owner:self options:nil];
        self = [(LoadingV*)[nibViews objectAtIndex: 0] retain];
    }
    return self;
}

我想知道:

1. 这样做是可以接受的吗?还有更好的办法吗?
2. 我应该保持"保留"，因为我不调用[自我释放]在dealloc?

干杯房颤

Answer 1

不，这是不可接受的，这是不好的做法，你实际上有内存泄漏。

更好的方法是使用一个叫做"factory"的模式。

的例子:

@interface CustomView: UIView
@end
@implementation CustomView
- (void)awakeFromNib {
    // custom view loaded from nib
}
@end
@interface UIView (Nib)
+ (UIView *)viewFromNib:(NSString *)nibName bundle:(NSBundle *)bundle;
@end
@implementation UIView (Nib)
+ (UIView *)viewFromNib:(NSString *)nibName bundle:(NSBundle *)bundle {
    if (!nibName || [nibName length] == 0) {
        return nil;
    }
    UIView *view = nil;
    if (!bundle) {
        bundle = [NSBundle mainBundle];
    }
    // I assume, that there is only one root view in interface file
    NSArray *loadedObjects = [bundle loadNibNamed:nibName owner:nil options:nil];
    view = [loadedObjects lastObject];
    return view;
}
@end

用法:

// CustomView.xib contains one View object with its class set to "CustomView"
CustomView *myView = (CustomView *)[UIView viewFromNib:@"CustomView" bundle:nil];