Question

我的iOS应用中有UIScrollView。在UIScrollView我有一个UITextView和一个UIImageView。我需要的是UIImageView滚动，直到它的底部大约33％从屏幕顶部移除然后粘住。

这是我的viewDidLoad：

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    CGRect fullScreenRect=[[UIScreen mainScreen] applicationFrame];
    UIScrollView *scrollView =[[UIScrollView alloc] initWithFrame:fullScreenRect];
    scrollView.contentSize = CGSizeMake(self.view.bounds.size.width, 758);

    self.view = scrollView;

    self.automaticallyAdjustsScrollViewInsets = NO;

    self.view.backgroundColor = [UIColor whiteColor];

    NSString *imageUrl = [NSString stringWithFormat: @"%@", [self.stream plaatje]];

    self.imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 64, self.view.bounds.size.width, self.view.frame.size.height-164)];
    [self.imageView sd_setImageWithURL:[NSURL URLWithString:imageUrl] placeholderImage:[UIImage imageNamed:@"tile-blue.png"]];
    [self.view addSubview:self.imageView];

UITextView *content = [[UITextView alloc] initWithFrame:CGRectMake(0, self.view.frame.size.height-100, self.view.bounds.size.width,     self.view.bounds.size.height)];
    content.text = textString;
    content.textColor = [UIColor blackColor];
    content.backgroundColor = [UIColor whiteColor];
    content.font = [UIFont fontWithName:@"SourceSansPro-Regular" size:18];
    content.textAlignment = NSTextAlignmentLeft;
    [content sizeToFit];
    [content layoutIfNeeded];
    [self.view addSubview:content];

    CGFloat width = self.view.bounds.size.width;
    CGFloat imageHeight = CGRectGetMaxY(self.imageView.frame);
    CGFloat contentHeight = CGRectGetMaxY(content.frame);
    [scrollView setContentSize:(CGSizeMake(width, contentHeight))];
}

现在，我对此做了一些研究，我95％确定我需要这样做：

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGRect headerFrame = self.imageView.frame;
    headerFrame.origin.y = MAX(self.imageView.frame.origin.y, scrollView.contentOffset.y);
    self.imageView.frame = headerFrame;
}

虽然目前的实施没有做任何事情。我该如何解决这个问题？

滚动缩小和粘贴UIImageView？

0 个答案: