我创建了具有内容插入的UIScrollView.
scrollView.frame = CGRectMake(-80,180,480,190) self.scrollView.contentInset = UIEdgeInsetsMake(0,160,160); self.scrollView.pagingEnabled = YES; [self.scrollView setContentSize:CGSizeMake(480,190)]; // Add three Views [self.scrollView addSubview:view1]; [self.scrollView addSubview:view2]; [self.scrollView addSubview:view3]; [view1 setFrame:CGRectMake(0,190)]; [view2 setFrame:CGRectMake(160,190)]; [view3 setFrame:CGRectMake(320,190)];
第一次,scrollView.contentOffset.x为-160.0
但是奇怪的问题是当我点击scrollView(黄色区域)时,内容偏移x值将重置为0并显示为这样.
我尝试过几次,但是点击滚动视图会将内容偏移量重置为0.
我该如何防止这种情况？
解决方法
UIScrollView分页通过滚动与scrollView宽度相同的页面(在您的情况下为480个宽度的页面).这意味着您有1个单页(由于160内容插入,您仍然可以左右滚动).
做这项工作的一个方法是：
self.scrollView.frame = CGRectMake(80,190); self.scrollView.clipsToBounds = NO; self.scrollView.contentInset = UIEdgeInsetsZero; self.scrollView.pagingEnabled = YES; [self.scrollView setContentSize:CGSizeMake(480,190)];
这将绘制和滚动正确,但是,屏幕的两侧将不会互动(每边80个像素,因为控件从frame.origin.x = 80开始,结束于80 160 = 240).
第二个选项是通过使用UIScrollViewDelegate提供的方法来处理分页.
- (void)viewDidLoad
{
[super viewDidLoad];
// pageIndex must be declared as a class member - this is used to prevent skipping pages during scroll
pageIndex = 0;
self.scrollView.frame = CGRectMake(0,320,190);
self.scrollView.contentInset = UIEdgeInsetsMake(0,80,80);
self.scrollView.pagingEnabled = NO;
self.scrollView.clipsToBounds = YES;
[self.scrollView setContentSize:CGSizeMake(480,190)];
self.scrollView.delegate = self;
}
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset{
int pageWidth = 160;
int pageX = pageIndex*pageWidth-scrollView.contentInset.left;
if (targetContentOffset->x<pageX) {
if (pageIndex>0) {
pageIndex--;
}
}
else if(targetContentOffset->x>pageX){
if (pageIndex<3) {
pageIndex++;
}
}
targetContentOffset->x = pageIndex*pageWidth-scrollView.contentInset.left;
NSLog(@"%d %d",pageIndex,(int)targetContentOffset->x);
}
