Xcode IOS 6 - 设置图像库scrollview

Question

我正在尝试使用下面的代码在IOS 6中设置可滚动的图库。它运行时没有错误，但滚动视图中没有显示任何内容。

图像在项目中，可以在Xcode中查看。此外，uiscrollview已连接到其IBoutlet。

NS Log语句确认调用了setupImgGallery（并且images数组包含6个项目），然后是showGallery。两者都来自

-(void)setupImgGallery
{
    NSLog(@"In setupImgGallery \n");

    UIImage *image1 = [UIImage imageNamed:@"1.png"];
    UIImage *image2 = [UIImage imageNamed:@"2.png"];
    UIImage *image3 = [UIImage imageNamed:@"3.png"];
    UIImage *image4 = [UIImage imageNamed:@"4.png"];
    UIImage *image5 = [UIImage imageNamed:@"5.png"];
    UIImage *image6 = [UIImage imageNamed:@"6.png"];

    images = [[NSArray alloc] initWithObjects:image1,image2,image3,image4,image5,image6,nil];


    imgScrollView.pagingEnabled = YES;
    [imgScrollView setIndicatorStyle:UIScrollViewIndicatorStyleDefault];

    NSLog(@"Count is |%d|\n",images.count);
    int numberOfViews = 6;
    for (int i = 0; i < numberOfViews; i++)
    {
        CGFloat xOrigin = i * IMAGE_WIDTH;

        tmpimageView = [[UIImageView alloc]    initWithFrame:CGRectMake(xOrigin,0,IMAGE_WIDTH,IMAGE_WIDTH)];
         [tmpimageView setImage:[images objectAtIndex:i]];
         [imgScrollView addSubview:tmpimageView];

    }

    imgScrollView.contentSize = CGSizeMake(numberOfViews * IMAGE_WIDTH, IMAGE_WIDTH);
    imgScrollView.scrollEnabled = TRUE;
}

- (void)showGallery
{
    NSLog(@"In showGallery \n");
    singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTapGestureCaptured:)];

    //Default value for cancelsTouchesInView is YES, which will prevent buttons to be clicked
    singleTap.cancelsTouchesInView = NO;
    [imgScrollView addGestureRecognizer:singleTap];
    flipped=FALSE;

    }

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    [mainView setTranslatesAutoresizingMaskIntoConstraints:NO];
    [self setupImgGallery];
    [self showGallery];  
}