ios28--UIScrollView

//
//  ViewController.m
//  UIScrollVIew

#import "ViewController.h"

@interface ViewController ()<UIScrollViewDelegate>
@property (weak, nonatomic) IBOutlet UIScrollView *scrollView;//已经设置大小是300*200
@property (weak, nonatomic) IBOutlet UIScrollView *scrollView1;
@property (weak, nonatomic) IBOutlet UIScrollView *scrollView2;

@end

@implementation ViewController

- (void)viewDidLoad {//控制器类加载完毕后
    [super viewDidLoad];
    
    //1、
    UIView *redView = [[UIView alloc]init];
    redView.backgroundColor = [UIColor redColor];
    redView.frame = CGRectMake(0, 0, 50, 50);
    [self.scrollView addSubview:redView];
    self.scrollView.clipsToBounds = YES;
    //设置内容尺寸，水平不能滚动，垂直滚动10，
    self.scrollView.contentSize = CGSizeMake(300, 210);
    //self.scrollView.scrollEnabled = NO; 不可以滚动
    //是否能够跟用户交互
    self.scrollView.userInteractionEnabled = YES;
    [self.scrollView.subviews.firstObject removeFromSuperview];//移除
    NSLog(@"%@",self.scrollView.subviews);
    /*   另外2个是滚动条，
     (
     "<UIView: 0x7fae0340c7d0; frame = (0 0; 50 50); layer = <CALayer: 0x600000036740>>",
     "<UIImageView: 0x7fae035126b0; frame = (294.667 190; 2.33333 7); alpha = 0; opaque = NO; autoresize = LM; userInteractionEnabled = NO; layer = <CALayer: 0x608000030f60>> - (null)",
     "<UIImageView: 0x7fae03512090; frame = (290 194.667; 7 2.33333); alpha = 0; opaque = NO; autoresize = TM; userInteractionEnabled = NO; layer = <CALayer: 0x608000030da0>> - (null)"
     )
     */
    
    
    
    //2、加载大图片
    UIImageView* image = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"7"]];//大图片
    self.scrollView1.contentSize = CGSizeMake(image.frame.size.width, image.frame.size.height);
    self.scrollView1.bounces = YES;//弹簧效果
    self.scrollView1.alwaysBounceVertical = YES;//没有设置contentSize的时候，不能滚动，但是有时候网络加载的时候，没有数据，需要下拉刷新来加载数据，就用这个，
    self.scrollView1.alwaysBounceHorizontal = YES;
    self.scrollView1.showsVerticalScrollIndicator = YES;//是否显示滚动条
    [self.scrollView1 addSubview:image];
    self.scrollView1.contentInset = UIEdgeInsetsMake(10, 20, 30, 40);//内边距
    //self.scrollView1.contentOffset = CGPointMake(700, 700);//设置偏移
    NSLog(@"%f",self.scrollView1.contentOffset.x);//获取滚动的偏移量
    
    
    
    
    
    
    //3、下拉刷新，显示菊花。
    UIActivityIndicatorView *iv = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    iv.center = CGPointMake(100, -30);
    [iv startAnimating];
    self.scrollView2.backgroundColor = [UIColor yellowColor];
    self.scrollView2.alwaysBounceVertical = YES;//没有设置contentSize不能滚动，为了下载加载并显示菊花。（不能滚动，只是有弹簧效果）
    self.scrollView2.alwaysBounceHorizontal = NO;
    [self.scrollView2 addSubview:iv];
    
    
    
    
    
    //代理
    UIScrollView *s = [[UIScrollView alloc]init];
    s.backgroundColor = [UIColor redColor];
    s.frame = CGRectMake(0, 20, 100, 100);
    [self.view addSubview:s];
    UIImage * i = [UIImage imageNamed:@"car"];
    UIImageView* imagev = [[UIImageView alloc]initWithImage:i];
    [s addSubview:imagev];
    s.contentSize = i.size;
    s.delegate = self;//代理，@property(nullable,nonatomic,weak) id<UIScrollViewDelegate>        delegate; 任何类型但是必须遵守UIScrollViewDelegate协议，在控制器加上遵守协议，@interface ViewController ()<UIScrollViewDelegate>，协议不写在.h文件中，因为.h文件暴露在外面给别人看的。
    
    
}

//点击控制器view的空白处调用
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    //self.scrollView1.contentOffset.y = 0;//不能直接修改oc对象的结构体变量的成员属性
    
    //点击回到顶部,并且添加动画
    [UIView animateWithDuration:2.0 animations:^{
        CGPoint cp = self.scrollView1.contentOffset;
        cp.y = 0;
        self.scrollView1.contentOffset = cp;
    }];
    
    //点击回到左边
    [self.scrollView1 setContentOffset:CGPointMake(0, self.scrollView1.contentOffset.y) animated:YES];
    NSLog(@"dddd");
}

-(void)scrollViewDidScroll:(UIScrollView *)scrollView //区域正在滚动时候调用
{
    
}

-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView //开始滚动时候调用
{

}

-(void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset//即将停止拖拽时候调用
{
    
}

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView//减速完毕调用
{
    
}
@end