//
//  ViewController.m
//  UI05_ScrollView
//
//  Created by lanou3g on 17/8/9.
//  Copyright © 2017年 lanou3g. All rights reserved.
//

#import "ViewController.h"

@interface ViewController () <UIScrollViewDelegate>

@property (nonatomic, retain) UIScrollView *scrollView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(100, 100, 200, 400)];
    scrollView.backgroundColor = [UIColor redColor];
    [self.view addSubview:scrollView];
    self.scrollView = scrollView;
    
    //设置scrollView的滑动范围(内容的实际尺寸)
    scrollView.contentSize = CGSizeMake(800, 800); // 可在区域范围内左右上下移动
    //设置scrollView的偏移量(x控制水平方向，y控制垂直方向)
    scrollView.contentOffset = CGPointMake(0, 100);
    //设置是否以动画的形式偏移
    [scrollView setContentOffset:CGPointMake(0, 100) animated:YES];
    //是否能触壁反弹(默认值是YES)
    scrollView.bounces = NO;
    //在scrollView的周围补充额外的滑动区域(上左下右)
    scrollView.contentInset = UIEdgeInsetsMake(200, 0, 0, 0);
    //锁定滑动方向
    scrollView.directionalLockEnabled = YES;
    //垂直没有回弹
//    scrollView.alwaysBounceVertical = YES;
    
    //默认值是NO，当该属性值为YES，且bounces为YES，在水平方向的滚动范围小于scrollView的bounces的宽度的时候，允许出现水平回弹效果
    //水平没有回弹
    scrollView.alwaysBounceHorizontal = YES;
    //以整页翻动(水平方向滑动每次为一个scrollView的frame宽度，垂直方向滑动每次为一个scrollView的frame的高度)
    scrollView.pagingEnabled = YES;
    //设置scrollView能否以动画的形式偏移
//    scrollView.scrollEnabled = NO;
    //关闭垂直方向的滑动指示器
//    scrollView.showsVerticalScrollIndicator = NO;
    //关闭水平方向的滑动指示器
//    scrollView.showsHorizontalScrollIndicator = NO;
    //滑动指示器样式
    scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
    
    //控制缩放的范围
    scrollView.delegate = self;
    scrollView.minimumZoomScale = 0.5f;
    scrollView.maximumZoomScale = 2.0f;
    
    //设置scrollview缩放倍数
//    scrollView.zoomScale = 1.0;
    //轻拍回到顶部
    scrollView.scrollsToTop = YES;
    
    UIView *greenView = [[UIView alloc] initWithFrame:CGRectMake(50, 50, 100, 200)];
    greenView.backgroundColor = [UIColor greenColor];
    [scrollView addSubview:greenView];
    
    UIView *yellowView = [[UIView alloc] initWithFrame:CGRectMake(50, 300, 300, 400)];
    yellowView.backgroundColor = [UIColor yellowColor];
    [scrollView addSubview:yellowView];
    
    
}
//视图滑动时调用该方法 ＊＊＊＊＊
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
//    NSLog(@"scroll offset x:%lf, y:%lf",scrollView.contentOffset.x,scrollView.contentOffset.y);
    //偏移的透明度
    [[scrollView.subviews firstObject] setAlpha: scrollView.contentOffset.y/100];
    
    //判断是否要滑动到底部
    if (scrollView.contentSize.height-scrollView.contentOffset.y-scrollView.frame.size.height <= 50) {
        NSLog(@"还有不到50个点就要滑动到底部");
    }
}

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return [scrollView.subviews firstObject];
}
//开始拖5
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
    NSLog(@"------------drag begin");
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
    NSLog(@"drag end");
}

- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView {
    NSLog(@"decelerate begin");
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
    NSLog(@"decelerate end");
}

- (void)viewDidAppear:(BOOL)animated {
    [self.scrollView setContentOffset:CGPointMake(100, 400) animated:YES];
}
//当我们调用setcontentoffset:animated：方法时，触发偏移动画，该动画结束时（到达偏移位置时）会调用此方法
- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView {
    NSLog(@"scroll animation end");
}
//缩放时调用方法
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
    NSLog(@"zoom");
}

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

@end