UIScrollView滚动视图

一、基本知识

1、初始化 UIScrollView

#import "ViewController.h"
#define WIDTH[[UIScreen mainScreen]bounds].size.width
#define HEIGHT[[UIScreen mainScreen]bounds].size.height
@interface ViewController ()<UIScrollViewDelegate>

@end

UIScrollView *scroll = [[UIScrollView alloc]initWithFrame:CGRectMake(10, 20, WIDTH-20, HEIGHT-30)];

2、设置属性

UIScrollView *scroll = [[UIScrollViewalloc]initWithFrame:CGRectMake(10, 20, WIDTH-20, HEIGHT-30)];

scroll.backgroundColor = [UIColor greenColor];
    scroll.contentSize = CGSizeMake((WIDTH-20)*10, HEIGHT+30);;//设置滚动范围，如果想要左右滑动，则必须保证此宽大于scroll的frame对应的宽，如果想要上下滑动必须保证此高大于scroll的frame对应的高
    //scroll.scrollEnabled = YES;//是否允许滚动
    scroll.bounces = YES;//是否有弹簧效果
    //scroll.contentOffset =CGPointMake(40, 80);//设置scrollview滚动到某个位置
    NSLog(@"%@",NSStringFromCGPoint(scroll.contentOffset));//获取scrollview当前滚动的位置
                                     
    scroll.pagingEnabled = YES;//是否允许整页滚动，如果想要左右整页滑动，要保证contentsize的宽是scrollview frame宽的整数倍，如果要上下整页滑动，要保证contentsize 的高是frame高的整数倍，当下一页露出范围小于整页的一半时，滚回到当前页，当超出一半时，滚动到下一页
    //scroll.showsHorizontalScrollIndicator = NO;//是否显示水平滚动条
    //scroll.showsVerticalScrollIndicator = NO;//是否显示垂直滚动条
    //scroll.scrollsToTop = YES;//点状态栏时，是否允许scorllView滚动到顶部
    //scroll.zooming = YES;//是否允许缩放

    scroll.zoomScale = 2;

3、 [self.view addSubview:scroll];

4、 UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(10, 10, 60, 30)];
    label.backgroundColor = [UIColor redColor];
    [scroll addSubview:label];
   
    for (int i=1; i<4; i++) {
        UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"%d.jpg",i]];
        //    float w = image.size.width;
        //    float h =image.size.height;
        UIImageView *imageview = [[UIImageView alloc]initWithImage:image];
        imageview.frame = CGRectMake(30+i*375, 60, 300, 550);
        [scroll addSubview:imageview];

    }

 二、例子

#import "ViewController.h"
@interface ViewController ()<UIScrollViewDelegate>
{
    UISegmentedControl *segment;
    UIScrollView *scrollView;
}
@end
@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(10, 30, 300, 400)];
    scrollView.backgroundColor = [UIColor whiteColor];
    scrollView.contentSize = CGSizeMake(900, 400);
    scrollView.delegate = self;
    scrollView.pagingEnabled = YES;
    scrollView.scrollEnabled = NO;
    [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];
   
    segment = [[UISegmentedControl alloc] initWithItems:@[@"1",@"2",@"3"]];
    segment.frame = CGRectMake(10, 450,200, 40);
    segment.selectedSegmentIndex = 0;
    [segment addTarget:self action:@selector(segmentChange) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:segment];
   
}
-(void)segmentChange{
    CGPoint p = {segment.selectedSegmentIndex*300,0};
    [scrollView setContentOffset:p animated:YES];
}
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
   // NSLog(@"滑动时调用");
}

-(void)scrollViewDidScrollToTop:(UIScrollView *)scrollView{
    //点击状态栏调用（scrolltotop = yes）
   // NSLog(@"到顶了");
}

-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
    //手指放到scrollview上开始滑动时调用
   // NSLog(@"调用");
}

-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
    //停止拖拽
   // NSLog(@"--->停止");
}

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
    //停止减速--scrollview不动了
  //  NSLog(@"不动了");
   
    CGPoint p = scrollView.contentOffset;
    float w = p.x;

int index = w/scrollView.frame.size.width;
    NSLog(@"当前：%d页",index);
   
    segment.selectedSegmentIndex = index;
   

}