UIScroll在iPhone中查看当前位置

Question

Suppose I have a scroll view in a view & a scroll view's size is 320 width, 2000 height.

When user scrolls & decelerating stops, I want to know where a scroll view has stopped?

ie at 300px or 400px or at 600px.

Answer 1

you can track that afeter scrolling, what is the coordinate of the origin, using the following two methods. This are two delegate methods conforms to your UIScrollView class.

-

 (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)newScrollView
{
    NSLog(@"scrollViewDidEndScrollingAnimation");
    CGPoint p = scrollView.contentOffset;


    int curr= floor(p.x/320);

    NSLog(@"x=%f,y=%f,curr=%d",p.x,p.y,curr);

}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)newScrollView
{

    [self scrollViewDidEndScrollingAnimation:newScrollView];

}

Answer 2

使用scrollview.contentOffset。

Answer 3

When the scroll view is done scrolling, it fires off some events to its UIScrollViewDelegate :

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

You can implement those methods in the delegate to find out the new contentOffset of your UIScrollView :

@property(nonatomic) CGPoint contentOffset

Answer 4

You can find out where any view is situated relative to its superview by looking at its frame rect. What are you trying to do?