好的,我使用嵌套的 UIScrollViews 找到了我自己问题的解决方案。我还向 github 添加了一个非常粗略的解决方案作为项目:https ://github.com/cohen72/InfiniteDeckScroller 。
对于水平滚动,我有三个水平滚动视图,一个嵌套在另一个中。UIScrollview 会自动处理每个的正确滚动。根据内容偏移量和正在滚动的滚动视图,我知道如何“重新排列/重新排序”嵌套的滚动视图。
这是我提出的解决方案的片段。
这个特殊的解决方案允许向上滑动以显示,但是我还没有实现向下滑动以覆盖,但是这样做会使用与水平解决方案相同的方法。
#define BOTTOM 1
#define MIDDLE 2
#define TOP 3
#define VERTICAL_SUB 4
- (void)viewDidLoad{
[super viewDidLoad];
UIScrollView *scroll1 = [[UIScrollView alloc] initWithFrame:self.view.bounds];
UIScrollView *scroll2 = [[UIScrollView alloc] initWithFrame:self.view.bounds];
UIScrollView *scroll3 = [[UIScrollView alloc] initWithFrame:self.view.bounds];
UIScrollView *scroll4 = [[UIScrollView alloc] initWithFrame:self.view.bounds];
scroll1.contentSize = CGSizeMake(self.view.frame.size.width * 2, self.view.frame.size.height * 1);
scroll1.tag = BOTTOM;
scroll1.pagingEnabled = YES;
scroll1.bounces = NO;
scroll1.delegate = self;
[scroll1 addSubview:[self labelForScrollView:scroll1 withBgColor:[UIColor redColor]]];
[scroll1 setContentOffset:CGPointMake(0, 0)];
scroll2.contentSize = CGSizeMake(self.view.frame.size.width * 2, self.view.frame.size.height * 1);
scroll2.tag = MIDDLE;
scroll2.pagingEnabled = YES;
scroll2.bounces = NO;
scroll2.delegate = self;
[scroll2 addSubview:[self labelForScrollView:scroll2 withBgColor:[UIColor orangeColor]]];
[scroll2 setContentOffset:CGPointMake(0, 0)];
scroll3.contentSize = CGSizeMake(self.view.frame.size.width * 2, self.view.frame.size.height * 1);
scroll3.tag = TOP;
scroll3.pagingEnabled = YES;
scroll3.bounces = NO;
scroll3.delegate = self;
[scroll3 addSubview:[self labelForScrollView:scroll3 withBgColor:[UIColor yellowColor]]];
[scroll3 setContentOffset:CGPointMake(320, 0)];
scroll4.contentSize = CGSizeMake(self.view.frame.size.width * 1, self.view.frame.size.height * 2);
scroll4.delegate = self;
scroll4.bounces = NO;
scroll4.pagingEnabled = YES;
scroll4.alwaysBounceVertical = NO;
scroll4.tag = VERTICAL_SUB;
[scroll4 addSubview:scroll1];
[scroll1 addSubview:scroll2];
[scroll2 addSubview:scroll3];
[self.view addSubview:scroll4];
}
- (UILabel*)labelForScrollView:(UIScrollView*)scrollView withBgColor:(UIColor*)color{
UILabel *lbl = [[UILabel alloc] initWithFrame:scrollView.bounds];
lbl.textAlignment = NSTextAlignmentCenter;
lbl.backgroundColor = color;
lbl.text = [NSString stringWithFormat:@"ScrollView: %d", scrollView.tag];
return lbl;
}
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
NSLog(@"content offset: %f, tag: %d ", scrollView.contentOffset.x, scrollView.tag);
UIScrollView *newMiddleScrollView, *newBottomScrollView, *newTopScrollView;
// swipe left
if (scrollView.contentOffset.x == 0 && scrollView.tag == TOP) {
newMiddleScrollView = (UIScrollView*)[self.view viewWithTag:TOP];
newTopScrollView = (UIScrollView*)[self.view viewWithTag:BOTTOM];
newBottomScrollView = (UIScrollView*)[self.view viewWithTag:MIDDLE];
}
// swipe right
else if (scrollView.contentOffset.x == 320 && scrollView.tag == MIDDLE) {
newMiddleScrollView = (UIScrollView*)[self.view viewWithTag:BOTTOM];
newTopScrollView = (UIScrollView*)[self.view viewWithTag:MIDDLE];
newBottomScrollView = (UIScrollView*)[self.view viewWithTag:TOP];
}
else {
return;
}
newMiddleScrollView.tag = MIDDLE;
newBottomScrollView.tag = BOTTOM;
newTopScrollView.tag = TOP;
newBottomScrollView.contentOffset = CGPointMake(0, 0);
newMiddleScrollView.contentOffset = CGPointMake(0, 0);
newTopScrollView.contentOffset = CGPointMake(320, 0);
UIScrollView *verticalScrollView_sub = (UIScrollView*)[self.view viewWithTag:VERTICAL_SUB];
[verticalScrollView_sub addSubview:newBottomScrollView];
[newBottomScrollView addSubview:newMiddleScrollView];
[newMiddleScrollView addSubview:newTopScrollView];
}