ios 学习 广告图片轮播器

 

//
//  ViewController.m
//  图片轮播器
//
//  Created by zjj on 15/5/23.
//  Copyright (c) 2015年 zjj. All rights reserved.
//

#import "ViewController.h"
#define kCount 5
@interface ViewController () <UIScrollViewDelegate>
@property (nonatomic,strong)UIScrollView *scroView;
@property (nonatomic,strong)UIPageControl *pageControl;
@property (nonatomic,strong)NSTimer *time;
@end

@implementation ViewController
/**
 开发思路
 1>创建scrollView  
 2>用UIimageView加载图片 并修改图片的x值
 3>创建分页控件UIpageControl 
 4>绑定分页圆点点 点击圆点点换下一页
 5>绑定时钟
 */
#pragma mark 初始化scrollView
- (UIScrollView *)scroView
{
    if (_scroView == nil) {
        _scroView = [[UIScrollView alloc]initWithFrame:CGRectMake(36, 20, 300, 130)];
        _scroView.backgroundColor = [UIColor blueColor];
        [self.view addSubview:_scroView];
        _scroView.bounces = NO;
        _scroView.showsHorizontalScrollIndicator = NO;
        _scroView.showsVerticalScrollIndicator = NO;
        _scroView.contentSize = CGSizeMake(_scroView.bounds.size.width * kCount, 0);
        self.scroView.pagingEnabled = YES;
        _scroView.delegate = self;
    }
    return _scroView ;
}
#pragma mark 初始化PageCOntrol
- (UIPageControl *)pageControl
{
    if (_pageControl == nil) {
        // 分页控件 跟scrollView 是独立的
        _pageControl = [[UIPageControl alloc]init];
        _pageControl.numberOfPages = kCount;
        CGSize size = [_pageControl sizeForNumberOfPages:kCount];
        _pageControl.bounds = CGRectMake(0, 0, size.width, size.height);
        _pageControl.center = CGPointMake(self.scroView.center.x, self.scroView.center.y+(self.scroView.center.y/2));
        _pageControl.pageIndicatorTintColor = [UIColor redColor];
        _pageControl.currentPageIndicatorTintColor = [UIColor blackColor];
        [self.view addSubview:_pageControl];
        self.pageControl = _pageControl;
    }
    return _pageControl;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    for (int i = 0; i < kCount; i++) {
       NSString *icon = [NSString stringWithFormat:@"img_%02d",i + 1];
        UIImageView *imgView = [[UIImageView alloc]initWithFrame:self.scroView.bounds];
        imgView.image = [UIImage imageNamed:icon];
        [self.scroView addSubview:imgView];
    }
    // 添加事件之后执行该块代码重新赋值x值
    [self.scroView.subviews enumerateObjectsUsingBlock:^(UIImageView *imageView, NSUInteger idx, BOOL *stop) {
        CGRect frame = imageView.frame;
        frame.origin.x = idx * frame.size.width;
        imageView.frame = frame;
    }];
    self.pageControl.currentPage = 0;
    [self.pageControl addTarget:self action:@selector(pageChange:) forControlEvents:UIControlEventTouchUpInside];
    [self start];
}
#pragma mark 启动时钟
- (void)start
{
//    self.time = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(changeTime) userInfo:nil repeats:YES];// 按住屏幕 画面会停止轮播但 时钟会累积 连跳好几页
    self.time = [NSTimer timerWithTimeInterval:2.0 target:self selector:@selector(changeTime) userInfo:nil repeats:YES];// 按住屏幕时钟 画面仍然不会停止轮播
    [[NSRunLoop currentRunLoop] addTimer:self.time forMode:NSRunLoopCommonModes];// 添加到（运行循环）轮循
}

- (void)changeTime
{
    int page = (self.pageControl.currentPage + 1) % kCount;
    self.pageControl.currentPage = page;
    [self pageChange:self.pageControl];
}

#pragma mark 对scrollView进行操作 根据图片偏移位置计算页数
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
//    NSLog(@"%@,%f",  NSStringFromCGPoint(_scroView.contentOffset),_scroView.bounds.size.width);//取出scrollview中当前页的x
    int page = _scroView.contentOffset.x / _scroView.bounds.size.width;
    self.pageControl.currentPage = page; //当前页数
}

- (void)pageChange :(UIPageControl *)page
{
    CGFloat x  = page.currentPage * self.scroView.bounds.size.width;
    [self.scroView setContentOffset:CGPointMake(x, 0)animated:YES];
}
#pragma mark 拖动图片时停止时钟
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    [self.time invalidate];
}
#pragma mark 松手后再次启动时钟
- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
{
    [self start];
}
@end