objective-c实现轮播图(17-08-09)

屏幕快照 2017-08-09 下午8.39.01.png 屏幕快照 2017-08-09 下午8.43.35.png

注：轮播图是7张，但要给8张图片，并且第一张和最后一张是同一张图片

//
//  ViewController.m
//  轮播图
//
//  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;
@property (nonatomic, retain) UIPageControl *pageControl;
@property (nonatomic, assign) NSTimer *timer;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    self.scrollView = [[UIScrollView alloc] initWithFrame:[UIScreen mainScreen].bounds];
    self.scrollView.delegate = self;
    self.scrollView.contentSize = CGSizeMake(self.view.frame.size.width*7, self.view.frame.size.height);
    [self.view addSubview:self.scrollView];
    
    for (int i = 1; i <= 8; i++) {
        NSString *imageName1 = [NSString stringWithFormat:@"h%d.jpeg",i];
        CGFloat x = (i-1)*self.view.frame.size.width;
        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(x, 0, self.view.frame.size.width, self.view.frame.size.height)];
        imageView.image = [UIImage imageNamed:imageName1];
        [self.scrollView addSubview:imageView];
    }
    self.scrollView.pagingEnabled = YES;
    self.scrollView.bounces = NO;
    
    self.pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(100, 25, self.view.frame.size.width-200, 30)];
    self.pageControl.numberOfPages = 7;
    self.pageControl.currentPage = 0;
    [self.pageControl addTarget:self action:@selector(pageControlAction) forControlEvents:UIControlEventEditingChanged];
    [self.view addSubview:self.pageControl];
    
    self.timer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(timerAction) userInfo:nil repeats:YES];
    [self.timer fire];
    
}
- (void)timerAction{
    CGFloat offsetX = self.scrollView.contentOffset.x;
    CGFloat offsetY = self.scrollView.contentOffset.y;
    CGFloat width = self.view.frame.size.width;
    [self.scrollView setContentOffset:CGPointMake(offsetX+width, offsetY) animated:YES];
    if (self.scrollView.contentOffset.x >= width * 7) {
        CGPoint point = CGPointMake(0, 0);
        self.scrollView.contentOffset = point;
    }
}

- (void)pageControlAction{
    CGFloat index = self.pageControl.currentPage;
    CGPoint point = CGPointMake(index*self.view.frame.size.width, 0);
    [self.scrollView setContentOffset:point animated:YES];
    
}


- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView {
    [self.timer invalidate];
    self.timer = nil;
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
    self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timerAction) userInfo:nil repeats:YES];
    [self.timer fire];
}


- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGFloat x = scrollView.contentOffset.x;
    CGFloat width = self.view.frame.size.width;
    if (x>=width*7) {
        self.pageControl.currentPage = 0;
    }else {
        self.pageControl.currentPage = x/width;
    }
}

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

@end