day 027 UIScrollView

//
//  ViewController.h
//  UIScrollView
//
//  Created by PXD on 15-5-1.
//  Copyright (c) 2015年 PXD. All rights reserved.
//


#import <UIKit/UIKit.h>


@interface ViewController : UIViewController<UIScrollViewDelegate>




@end

//
//  ViewController.m
//  UIScrollView
//
//  Created by PXD on 15-5-1.
//  Copyright (c) 2015年 PXD. All rights reserved.
//


#import "ViewController.h"


typedef enum{
    kScrollDirectionRight,
    kScrollDirectionLeft
}kScrollDirection;


@interface ViewController ()
@property (nonatomic, strong) UIScrollView *scrooView;
@property (nonatomic, assign) kScrollDirection direction;
@property (nonatomic, strong) UIPageControl *pageController;
@end


@implementation ViewController


- (void)viewDidLoad {
    [super viewDidLoad];
    
    _direction = kScrollDirectionRight;
    
    //frame 滚动视图的大小 看得到的界面的大小
    self.scrooView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 20, 320, 200)];
    _scrooView.backgroundColor = [UIColor lightGrayColor];
    
    //添加内容
    for (int i = 1; i <= 5; i++){
        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake((i-1)*320, 0, 320, 200)];
        imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%d", i]];
        [_scrooView addSubview:imageView];
    }
    
    //设置内容视图的宽高
    //width > scrollView.width   横向滚动
    //height > scrollView.height 纵向滚动
    //都超出scrooView的范围  双向滚动
    //都小于scrollView的范围 不滚动
    _scrooView.contentSize = CGSizeMake(5 * 320, 200);
    
    //设置按页显示
    _scrooView.pagingEnabled = YES;
    
    //隐藏横向的滚动条
    _scrooView.showsHorizontalScrollIndicator = NO;
    
    _scrooView.delegate = self;
    
    [self.view addSubview:_scrooView];
    
    UIButton *changeButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [changeButton setFrame:CGRectMake(100, 250, 120, 50)];
    [changeButton setTitle:@"滚动" forState:UIControlStateNormal];
    [changeButton addTarget:self action:@selector(buttonDidClicked) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:changeButton];
    
    //添加页码
    self.pageController = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 200, 320, 20)];
    //设置总共多少页
    _pageController.numberOfPages = 5;
    //当前第几页
    _pageController.currentPage = 0;
    [self.view addSubview:_pageController];
}


- (void)buttonDidClicked{
    //切换到下一张图片 contentOffset
    //NSLog(@"1---%.0f", _scrooView.contentOffset.x);
    
    CGFloat offsetX = 0;
    if (_direction == kScrollDirectionRight) {
        offsetX = _scrooView.contentOffset.x + 320;
        
        if (offsetX >= _scrooView.contentSize.width) {
            _direction = kScrollDirectionLeft;
        }
    }
    
    if (_direction ==kScrollDirectionLeft){
        offsetX = _scrooView.contentOffset.x - 320;
        
        if (offsetX <= 0) {
            _direction =kScrollDirectionRight;
        }
    }
    //NSLog(@"2--%.0f", offsetX);
    [_scrooView setContentOffset:CGPointMake(offsetX, 0) animated:YES];
    
    
}


#pragma mark -- ScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
    //获取当前的偏移值－> 获取当前的页数
    int page = scrollView.contentOffset.x / 320;
    
    
    if (page != _pageController.currentPage) {
        //设置页码
        [_pageController setCurrentPage:page];
    }
   
}


////即将滚动
//- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
//    NSLog(@"将要拖动");
//}
//
////正在滚动
//- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
//    NSLog(@"正在滚动");
//}
//
////滚动结束了
//- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
//    NSLog(@"拖动结束");
//}
//
//- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView{
//    NSLog(@"手放开 惯性运动");
//}
//
//- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
//    NSLog(@"惯性运动结束  停下来了");
//}


@end