#import "ViewController.h"
#define SCREEN_WIDTH [UIScreen mainScreen].bounds.size.width
#define SCREEN_HEIGHT [UIScreen mainScreen].bounds.size.height
#define IMAGEVIEW_COUNT 3
@interface ViewController () <UIScrollViewDelegate> {
UIScrollView *_scrollView;
UIImageView *_leftImageView;
UIImageView *_centerImageView;
UIImageView *_rightImageView;
UIPageControl *_pageControl;
UILabel *_label;
NSMutableDictionary *_imageData;//图片数据
int _currentImageIndex;//当前图片索引
int _imageCount;//图片总数
}
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
//加载数据
[self loadImageData];
//添加滚动控件
[self addScrollView];
//添加图片控件
[self addImageViews];
//添加分页控件
[self addPageControl];
//添加图片信息描述控件
[self addLabel];
//加载默认图片
[self setDefaultImage];
}
#pragma mark 加载图片数据
-(void)loadImageData {
//读取程序包路径中的资源文件
NSString *path = [[NSBundle mainBundle] pathForResource:@"imageInfo" ofType:@"plist"];
_imageData = [NSMutableDictionary dictionaryWithContentsOfFile:path];
_imageCount = (int)_imageData.count;
}
#pragma mark 添加控件
-(void)addScrollView {
// _scrollView = [[UIScrollView alloc] initWithFrame:[UIScreen mainScreen].bounds];
_scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 20+20, SCREEN_WIDTH, 200)];
_scrollView.backgroundColor = [UIColor lightGrayColor];
//设置代理
_scrollView.delegate = self;
//设置滚动范围
_scrollView.contentSize = CGSizeMake(IMAGEVIEW_COUNT*SCREEN_WIDTH, 0);
//设置当前显示的位置为中间图片（设置scrollView偏移量）
[_scrollView setContentOffset:CGPointMake(SCREEN_WIDTH, 0)];
//设置分页
_scrollView.pagingEnabled = YES;
//隐藏水平条 竖向条
_scrollView.showsHorizontalScrollIndicator = NO;
_scrollView.showsVerticalScrollIndicator = NO;
//关闭弹簧效果
// _scrollView.bounces = NO;
[self.view addSubview:_scrollView];
}
#pragma mark 添加图片三个控件
-(void)addImageViews {
_leftImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, _scrollView.frame.size.height)];
//会保证图片比例不变，而且全部显示在ImageView中，这意味着ImageView会有部分空白
_leftImageView.contentMode=UIViewContentModeScaleAspectFit;
[_scrollView addSubview:_leftImageView];
_centerImageView = [[UIImageView alloc] initWithFrame:CGRectMake(SCREEN_WIDTH, 0, SCREEN_WIDTH, _scrollView.frame.size.height)];
_centerImageView.contentMode = UIViewContentModeScaleAspectFit;
[_scrollView addSubview:_centerImageView];
_rightImageView = [[UIImageView alloc] initWithFrame:CGRectMake(2*SCREEN_WIDTH, 0, SCREEN_WIDTH, _scrollView.frame.size.height)];
_rightImageView.contentMode = UIViewContentModeScaleAspectFit;
[_scrollView addSubview:_rightImageView];
}
#pragma mark 设置默认显示图片
-(void)setDefaultImage {
//加载默认图片
_leftImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%i.jpeg",_imageCount-1]];
_centerImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%i.jpeg",0]];
_rightImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%i.jpeg",1]];
_currentImageIndex = 0;
//设置当前页
_pageControl.currentPage = _currentImageIndex;
NSString *imageName = [NSString stringWithFormat:@"%i.jpeg",_currentImageIndex];
_label.text = _imageData[imageName];
}
#pragma mark 添加分页控件
-(void)addPageControl {
_pageControl = [[UIPageControl alloc] init];
// _pageControl.backgroundColor = [UIColor orangeColor];
//注意此方法可以根据页数返回UIPageControl合适的大小
CGSize size = [_pageControl sizeForNumberOfPages:_imageCount];
_pageControl.bounds = CGRectMake(0, 0, size.width, size.height);
_pageControl.center = CGPointMake(SCREEN_WIDTH*2/3, _scrollView.frame.origin.y+_scrollView.frame.size.height-10);
//设置颜色
_pageControl.pageIndicatorTintColor = [UIColor colorWithRed:193/255.0 green:219/255.0 blue:249/255.0 alpha:1];
//设置当前页颜色
_pageControl.currentPageIndicatorTintColor = [UIColor colorWithRed:0 green:150/255.0 blue:1 alpha:1];
//设置总页数
_pageControl.numberOfPages = _imageCount;
[self.view addSubview:_pageControl];
}
#pragma mark 添加信息描述控件
-(void)addLabel {
_label = [[UILabel alloc] initWithFrame:CGRectMake(0, 20, SCREEN_WIDTH, 20)];
// _label.backgroundColor = [UIColor orangeColor];
_label.textAlignment = NSTextAlignmentCenter;
_label.textColor = [UIColor colorWithRed:0 green:150/255.0 blue:1 alpha:1];
[self.view addSubview:_label];
}
#pragma mark 滚动停止事件
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
//重新加载图片
[self reloadImage];
//移动到中间
[_scrollView setContentOffset:CGPointMake(SCREEN_WIDTH, 0)];
//设置分页
_pageControl.currentPage = _currentImageIndex;
//设置描述
NSString *imageName = [NSString stringWithFormat:@"%i.jpeg",_currentImageIndex];
_label.text = _imageData[imageName];
}
#pragma mark 重新加载图片
-(void)reloadImage {
int leftImageIndex,rightImageIndex;
CGPoint offset = [_scrollView contentOffset];
if (offset.x > SCREEN_WIDTH) { //向右滑动
_currentImageIndex = (_currentImageIndex+1)%_imageCount;
}else if(offset.x < SCREEN_WIDTH) { //向左滑动
_currentImageIndex = (_currentImageIndex+_imageCount-1)%_imageCount;
}
_centerImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%i.jpeg",_currentImageIndex]];
//重新设置左右图片
leftImageIndex = (_currentImageIndex+_imageCount-1)%_imageCount;
rightImageIndex = (_currentImageIndex+1)%_imageCount;
_leftImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%i.jpeg",leftImageIndex]];
_rightImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%i.jpeg",rightImageIndex]];
}
@end