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我正在尝试设置无限(水平)滚动的滚动视图.

向前滚动很容易 - 我已经实现了scrollViewDidScroll,当contentOffset接近结尾时,我将使scrollview内容更大,并将更多数据添加到空间中(我将不得不处理稍后会产生的严重影响!)

我的问题是向后滚动 - 计划是看到我何时接近滚动视图的开头,然后当我确实使内容更大时,移动现有内容,将新数据添加到开头然后 - 重要的是调整contentOffset使视图端口下的数据保持不变.

如果我慢慢滚动(或启用分页),这可以很好地工作但如果我快速(甚至不是非常快!)它会发疯!下面是代码:

- (void) scrollViewDidScroll:(UIScrollView *)scrollView {

    float pageNumber = scrollView.contentOffset.x / 320;
    float pageCount = scrollView.contentSize.width / 320;

    if (pageNumber > pageCount-4) {
        //Add 10 new pages to end
        mainScrollView.contentSize = CGSizeMake(mainScrollView.contentSize.width + 3200, mainScrollView.contentSize.height);
        //add new data here at (320*pageCount, 0);
    }

    //*** the problem is here - I use updatingScrollingContent to make sure its only called once (for accurate testing!)
    if (pageNumber < 4 && !updatingScrollingContent) {

        updatingScrollingContent = …

我想像那样滚动1 2 3 1 2 3

我有一些按钮假设10我想在无尽的卷轴上显示.

 numbercolors=[[NSMutableArray alloc] init];

 //total count of array is  49 

 numbercolors = [NSMutableArray arrayWithObjects:@"25",@"26",@"27",@"28",@"29",@"31",@"32",@"33",@"34",@"35", @"0",@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10",@"11",@"12",@"13",@"14",@"15",@"16",@"17",@"18",@"19",@"20",@"21",@"22",@"23",@"24",@"25",@"26",@"27",@"28",@"29",@"30",@"31",@"32",@"33",@"34",@"35", @"0",@"1",@"2",@"3",nil];

  int x=2500;

for (NSInteger index = 0; index < [numbercolors count]; index++)
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];

    button.frame = CGRectMake(x ,0,29.0,77.0);

    button.tag = index;

    [button setTitle:[numbercolors objectAtIndex:index] forState:UIControlStateNormal];

    [button addTarget:self action:@selector(didTapButton:) 

    forControlEvents:UIControlEventTouchUpInside];

    [coloringScroll addSubview:button];

    x=x+70+29;
}
 [coloringScroll setContentSize:CGSizeMake(5000+ (29+70)*[numbercolors count], 1)];

 [coloringScroll setContentOffset:CGPointMake(2500+(29+70)*11, 0)];

这是我在scrollview上制作butttons的代码.

如何设置 - (void)scrollViewDidEndDecelerating :( UIScrollView*)发送方此方法进行无限滚动.