UIScrollView

Posted 2020-06-11

1.contentSize幕布实际大小决定滚动的方向，如果小于图片本身不滚动，默认也是不滚动

view.contentSize = CGSizeMake(1280, 200);

而frame只是用来显示UIScrollView的显示区域的大小用户看的到的。

2.页面效果，图片不可以停留在两张图中间

sview.pagingEnabled = YES;

3.是否有横向竖向滚动条,滚动条的样式黑色白色

sview.showsHorizontalScrollIndicator = NO;

sview.showsVerticalScrollIndicator = NO;

sview.indicatorStyle = UIScrollViewIndicatorStyleWhite;

4.边缘拉动弹簧效果

sview.bounces = YES;

5.设置不能滚动了

sview.scrollEnabled = NO;

6.表示滚动指示器从封闭滚动视图中被嵌入的距离

top right 作用于纵向

buttom left 作用于横向

sview.scrollIndicatorInsets = UIEdgeInsetsMake(0, 0, 0, 0);

7.内容滚动区域增加的距离

下拉刷新 上拉加载

sview.contentInset =UIEdgeInsetsMake(0, 0, 0, 0);

8.当前显示的位置

sview.contentOffset = CGPointMake(320*2, 0);

int page = scrollView.contentOffset.x/320.0;

9.常用代理方法

滚动中-(void)scrollViewDidScroll:(UIScrollView *)scrollView{}

即将开始拖动-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{} 

即将开始减速-(void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView{}

设置可以缩放的视图-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{}

10.最大放大倍数缩小倍数

sview.minimumZoomScale = 0.5;

sview.maximumZoomScale = 2;

sview.zoomScale目前拉伸的比例

放大缩小 只能对子视图进行缩放

-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{

    UIImageView * iview = [scrollView viewWithTag:1];

    return iview;

}

11.下方的小白点，不是UIScrollView上的，而是自己添加的

self.pageControl = [[UIPageControl alloc]initWithFrame:CGRectMake(0, 180, 320, 20)];

self.pageControl.numberOfPages = 4;

[_pageControl addTarget:self action:@selector(pageChanged) forControlEvents:UIControlEventValueChanged];

[self.view addSubview:_pageControl];

 

-(void)pageChanged{

    [_sview setContentOffset:CGPointMake(320*_pageControl.currentPage, 0) animated:YES];

}

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

    int page = scrollView.contentOffset.x/320.0;

    [self.pageControl setCurrentPage:page];

}