Question

我在滚动视图中有一个问题。

现在我用滚动视图写了一个关于图库的示例。我在滚动视图中添加了大量图像。每次显示3个图像，问题是如何正确测量滚动。例如：每个滚动最小移动1个图像。现在，我想每次滚动时，移动的最小图像都是3.这使我无法停留在我想看到的正确图像上。下面是代码。

- (void)layoutScrollImages
{
    UIImageView *view = nil;
    NSArray *subviews = [scroll subviews];

    // reposition all image subviews in a horizontal serial fashion
    CGFloat curXLoc = 0;
    for (view in subviews)
    {
        if ([view isKindOfClass:[UIImageView class]] && view.tag > 0)
        {
            CGRect frame = view.frame;
            frame.origin = CGPointMake(curXLoc, 0);
            view.frame = frame;

            curXLoc += (kScrollObjWidth);
        }
    }

    // set the content size so it can be scrollable
    [scroll setContentSize:CGSizeMake((kNumImages * kScrollObjWidth), [scroll bounds].size.height)];
}

#pragma mark - View lifecycle
- (void)viewDidLoad
{
    [super viewDidLoad];
    // 1. setup the scrollview for multiple images and add it to the view controller
    //
    // note: the following can be done in Interface Builder, but we show this in code for clarity
    [scroll setBackgroundColor:[UIColor blackColor]];
    [scroll setCanCancelContentTouches:NO];
    scroll.indicatorStyle = UIScrollViewIndicatorStyleWhite;
    scroll.clipsToBounds = YES;     // default is NO, we want to restrict drawing within our scrollview
    scroll.scrollEnabled = YES;

    // pagingEnabled property default is NO, if set the scroller will stop or snap at each photo
    // if you want free-flowing scroll, don't set this property.
    scroll.pagingEnabled = YES;

    // load all the images from our bundle and add them to the scroll view
    NSUInteger i;
    for (i = 1; i <= kNumImages; i++)
    {
        NSString *imageName = [NSString stringWithFormat:@"image%d.jpg", i];
        UIImage *image = [UIImage imageNamed:imageName];
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

        // setup each frame to a default height and width, it will be properly placed when we call "updateScrollList"
        CGRect rect = imageView.frame;
        rect.size.height = kScrollObjHeight;
        rect.size.width = kScrollObjWidth;
        imageView.frame = rect;
        imageView.tag = i;  // tag our images for later use when we place them in serial fashion
        [scroll addSubview:imageView];
        [imageView release];
    }

    [self layoutScrollImages];
}

Answer 1

使用此代码......

-(void)scrollViewDidScroll:(UIScrollView *)scrollView
 {
if(scroll.contentOffset.y> 320)
{

    int y  = scrollView.contentOffset.y;
    y = y/3;
    [scrollView setContentOffset:CGPointMake(0, y)];
}
}

希望，这会帮助你......寒冷

Answer 2

对内容视图进行子类化并覆盖此函数：

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
if ([self pointInside:point withEvent:event]) {
    if ([[self subviews] count] > 0) {
        //force return of first child, if exists
        return [[self subviews] objectAtIndex:0];
    } else {
        return self;
    }
}
return nil; }

详见https://github.com/taufikobet/ScrollViewCustomPaging。

如何在UIScrollView中自定义分页？

2 个答案: