UIView in NSCache being overriden - iphone

Question

I have a UIView that contains drop shadows and corners which I am loading four of in my UIViewController and I am seeing a performance hit when the screen loads. Since I am using the same white background with shadows and corner radii I figured I would store the UIView in NSCache.
When I run the app there is a large gap where the first UIView should be, however, it is not showing up. What does show up is the last view in my list of views. If I comment out the last one and run it again, the third one shows up. It seems like I am having an issue with the pointer in memory but not sure. Perhaps I am using NSCache incorrectly?
(Note: The first view shown is not using the NSCache)
Here is how I am using the NSCache:
.h file
#interface LunchDetailViewController : UIViewController <UIScrollViewDelegate>
#property (nonatomic) IBOutlet UIScrollView *scrollView;
#property (nonatomic, strong) NSCache *entreeViewsCache;
#end
.m file
#synthesize scrollView;
#synthesize entreeViewsCache;
- (void)viewDidLoad
{
[super viewDidLoad];
self.entreeViewsCache = [[NSCache alloc] init];
UIView *entreeView = [[UIView alloc] init];
entreeView.backgroundColor = [UIColor whiteColor];
entreeView.layer.masksToBounds = NO;
entreeView.layer.cornerRadius = 3.0;
entreeView.layer.shadowOffset = CGSizeMake(1.1, 2.1);
entreeView.layer.shadowOpacity = 0.2;
[self.entreeViewsCache setObject:entreeView forKey:#"EntreeView"];
}
- (void) configureScrollView
{
// This line of code allows the scroll view to be 'scrollable'.
self.scrollView.contentSize = CGSizeMake(320, 620);
UIView *elementaryRoundedCornerView = [self.entreeViewsCache objectForKey:#"EntreeView"];
elementaryRoundedCornerView.frame = CGRectMake(15,15,290,180);
UIView *middleRoundedCornerView = [self.entreeViewsCache objectForKey:#"EntreeView"];
middleRoundedCornerView.frame = CGRectMake(15,210,290,180);
UIView *highRoundedCornerView = [self.entreeViewsCache objectForKey:#"EntreeView"];
highRoundedCornerView.frame = CGRectMake(15,404,290,180);
NSMutableArray *entreeItems = [[NSMutableArray alloc] initWithObjects:#"Pancakes w/ Sausage Patties", #"Corn Dog", #"Grilled Cheese Sandwhich", #"Chicken Tender Wraps", nil];
UIView *elementaryLunchMenuDetails = [[UIView alloc] initWithFrame:CGRectMake(10, 10, 240, 160)];
[elementaryLunchMenuDetails addSubview:[self returnNativeCode:entreeItems rectDimensions:CGRectMake(2, 5, 215, 160) schoolType:#"Elementary"]];
[elementaryRoundedCornerView addSubview:elementaryLunchMenuDetails];
UIView *middleLunchMenuDetails = [[UIView alloc] initWithFrame:CGRectMake(10, 10, 240, 160)];
[middleLunchMenuDetails addSubview:[self returnNativeCode:entreeItems rectDimensions:CGRectMake(2, 2, 215, 160) schoolType:#"Middle"]];
[middleRoundedCornerView addSubview:middleLunchMenuDetails];
UIView *highLunchMenuDetails = [[UIView alloc] initWithFrame:CGRectMake(10,10, 240, 160)];
[highLunchMenuDetails addSubview:[self returnNativeCode:entreeItems rectDimensions:CGRectMake(2, 2, 215, 160) schoolType:#"High"]];
[highRoundedCornerView addSubview:highLunchMenuDetails];
[self.scrollView addSubview:elementaryRoundedCornerView];
[self.scrollView addSubview:middleRoundedCornerView];
[self.scrollView addSubview:highRoundedCornerView];
}

Answer 1

Wow. That's clever. But not correct.
Instead of using NSCache to duplicate a view, you probably want to create a UIView subclass that formats the view the way you want. Then just throw a bunch of those views on your scrollview.
ABCView.m
#implementation ABCDayView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.backgroundColor = [UIColor whiteColor];
self.layer.masksToBounds = NO;
self.layer.cornerRadius = 3.0;
self.layer.shadowOffset = CGSizeMake(1.1f, 2.1f);
self.layer.shadowOpacity = 0.2f;
}
return self;
}
- (void)setItems:(NSArray *)items
{
if ([_items isEqualToArray:items] == NO) {
_items = items;
[self createItemViews];
[self setNeedsLayout];
}
}
// You'll also need to add -createItemViews and -setNeedsLayout methods.
.m file
- (void)configureScrollView
{
NSMutableArray *entreeItems = #[#"Pancakes w/Sausage Patties",
#"Corn Dog",
#"Grilled Cheese Sandwhich",
#"Chicken Tender Wraps"];
CGRect frame = CGRectMake(15,15,290,180);
ABCDayView *elementaryView = [[ABCDayView alloc] initWithFrame:frame];
elementaryView.items = entreeItems;
CGFloat y = CGRectGetMaxY(elementaryView.frame) + 10.0f;
frame = CGRectMake(15, y, 290, 180);
ABCDayView *middleView = [[ABCDayView alloc] initWithFrame:frame];
middleView.items = entreeItems;
...
CGFloat length = // Use CGRectGetMaxY on the last frame to get the length.
self.scrollView.contentSize = CGSizeMake(320, length);
}
That's by no means perfect code. But hopefully it will give you an idea of a better way to implement this.