xcode 如何使 scrollView 自动滚动？
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how can I make a scrollView autoscroll?
提问by Mihai
I have this scrollView:
我有这个滚动视图：
self.scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
self.scrollView.autoresizingMask = UIViewAutoresizingFlexibleHeight;
self.scrollView.contentSize = CGSizeMake(320,3000);
_scrollView.frame = CGRectMake(0, 45, 320, 420);
and I want to make it autoscroll very slowly downward to the end so that the user can see the content (as in movie credits), eventually with a button to stop/play, but to follow the user gestures when touching the interface.
我想让它非常缓慢地向下自动滚动到最后，以便用户可以看到内容（如电影字幕中），最终有一个按钮来停止/播放，但在触摸界面时跟随用户手势。
How can I do this? Thanks,
我怎样才能做到这一点？谢谢，
采纳答案by Mihai
this adapted code did the trick (source http://sugartin.info/2012/01/21/image-sliding-page-by-page-uiscrollview-auto-scrolling-like-image-slider/)
这个改编的代码成功了（来源http://sugartin.info/2012/01/21/image-sliding-page-by-page-uiscrollview-auto-scrolling-like-image-slider/）
PS : each image is 280 by 200
PS：每张图片是 280 x 200
- (void)viewDidLoad
{
[super viewDidLoad];
UIScrollView *scr=[[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
scr.tag = 1;
scr.autoresizingMask=UIViewAutoresizingNone;
[self.view addSubview:scr];
[self setupScrollView:scr];
UIPageControl *pgCtr = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 264, 480, 36)];
[pgCtr setTag:12];
pgCtr.numberOfPages=10;
pgCtr.autoresizingMask=UIViewAutoresizingNone;
[self.view addSubview:pgCtr];
}
- (void)setupScrollView:(UIScrollView*)scrMain {
// we have 10 images here.
// we will add all images into a scrollView & set the appropriate size.
for (int i=1; i<=10; i++) {
// create image
UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"sti%02i.jpg",i]];
// create imageView
UIImageView *imgV = [[UIImageView alloc] initWithFrame:CGRectMake(20, ((i-1)*scrMain.frame.size.height+100), 280, 200)];
// set scale to fill
imgV.contentMode=UIViewContentModeScaleToFill;
// set image
[imgV setImage:image];
// apply tag to access in future
imgV.tag=i+1;
// add to scrollView
[scrMain addSubview:imgV];
}
// set the content size to 10 image width
[scrMain setContentSize:CGSizeMake(scrMain.frame.size.width, scrMain.frame.size.height*10)];
// enable timer after each 2 seconds for scrolling.
[NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(scrollingTimer) userInfo:nil repeats:YES];
}
- (void)scrollingTimer {
// access the scroll view with the tag
UIScrollView *scrMain = (UIScrollView*) [self.view viewWithTag:1];
// same way, access pagecontroll access
UIPageControl *pgCtr = (UIPageControl*) [self.view viewWithTag:12];
// get the current offset ( which page is being displayed )
CGFloat contentOffset = scrMain.contentOffset.y;
// calculate next page to display
int nextPage = (int)(contentOffset/scrMain.frame.size.height) + 1 ;
// if page is not 10, display it
if( nextPage!=10 ) {
[scrMain scrollRectToVisible:CGRectMake(0, nextPage*scrMain.frame.size.height, scrMain.frame.size.width, scrMain.frame.size.height) animated:YES];
pgCtr.currentPage=nextPage;
// else start sliding form 1 :)
} else {
[scrMain scrollRectToVisible:CGRectMake(0, 0, scrMain.frame.size.width, scrMain.frame.size.height) animated:YES];
pgCtr.currentPage=0;
}
}
回答by Apollo SOFTWARE
You can use:
您可以使用：
[_scrollView setContentOffset:CGPointMake(x,y) animated:YES];
and use the x and y as the touch points on the screen you can capture.
并使用 x 和 y 作为您可以捕获的屏幕上的触摸点。
You can also do an animation with CoreAnimation:
您还可以使用 CoreAnimation 制作动画：
[UIScrollView beginAnimations:@"scrollAnimation" context:nil];
[UIScrollView setAnimationDuration:1.0f];
[scroll setContentOffset:CGPointMake(x, y)];
[UIScrollView commitAnimations];
回答by iHS
You can set x if you want to scroll horizontally, otherwise set y to scroll vertical.
如果要水平滚动，可以设置 x，否则设置 y 以垂直滚动。
[_scrollView setContentOffset:CGPointMake(x, y) animated:YES];
and modify the co-ordinates accordingly.
并相应地修改坐标。
