IOS ——UI篇—— UIPageControl的使用以及与UIScrollView的结合

UIPageControl是分页符，在新闻类的APP中很常见，随着新闻页面的滚动，在屏幕中会有一些小点，也随着移动，用来分辨当前的页数，就是UIPageControl和ScrollView的结合使用；

直接给大家上代码，这样更有助于理解：

 page = [[UIPageControl alloc] initWithFrame:CGRectMake(20, 30, 200, 40)];
    page.backgroundColor = [UIColor clearColor];
    page.numberOfPages = 3;//设置页数（多少个点）
    page.currentPage = 0;//设置当前选中页
    NSLog(@"%d",page.currentPage);//获取当前选中页下标
    page.pageIndicatorTintColor = [UIColor greenColor];//未选中颜色
    page.currentPageIndicatorTintColor = [UIColor redColor];//当前选中的颜色
    [page addTarget:self action:@selector(change:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:page];

UIPageControl与UIScrollView 的结合使用

#import "ViewController.h"

@interface ViewController ()<UIScrollViewDelegate>{
    UIPageControl *page;
    UIScrollView  *scrollView;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    page = [[UIPageControl alloc] initWithFrame:CGRectMake(20, 30, 200, 40)];
    page.backgroundColor = [UIColor clearColor];
    page.numberOfPages = 3;//设置页数（多少个点）
    page.currentPage = 0;//设置当前选中页
    NSLog(@"%d",page.currentPage);//获取当前选中页下标
    page.pageIndicatorTintColor = [UIColor greenColor];//未选中颜色
    page.currentPageIndicatorTintColor = [UIColor redColor];//当前选中的颜色
    [page addTarget:self action:@selector(change:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:page];

    scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(20, 90, 300, 400)];
    scrollView.contentSize = CGSizeMake(900, 0);
    scrollView.delegate = self;
    scrollView.pagingEnabled = YES;
    [self.view addSubview:scrollView];

    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 300, 400)];
    view.backgroundColor = [UIColor grayColor];
    [scrollView addSubview:view];

    UIView *view1 = [[UIView alloc] initWithFrame:CGRectMake(300, 0, 300, 400)];
    view1.backgroundColor = [UIColor brownColor];
    [scrollView addSubview:view1];

    UIView *view2 = [[UIView alloc] initWithFrame:CGRectMake(600, 0, 300, 400)];
    view2.backgroundColor = [UIColor purpleColor];
    [scrollView addSubview:view2];


}

-(void)change:(id)page{
    NSLog(@"--%zi",[page currentPage]);

CGPoint p = {[page currentPage]*300,0};//获取分页符当前的页数与view的宽相乘作为CGPoint的x

 [scrollView setContentOffset:p animated:YES];//将p赋给scrollView的当前滚动位置，就建立了联系

}
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 -(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
int index = scrollView.contentOffset.x/scrollView.frame.size.width;//当scrollView滚动停止时，将scrollView当前滚动到的位置除以view的宽，获得的值就是页数

page.currentPage = index; //将上面获得的页数赋给page，就是page的当前页

} 

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- (void)didReceiveMemoryWarning {
 [super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.

}


@end