UI2_ScrollView&UIPageControl

//

//  ViewController.h

//  UI2_ScrollView&UIPageControl

//

//  Created by zhangxueming on 15/7/10.

//  Copyright (c) 2015年 zhangxueming. All rights reserved.

//



#import <UIKit/UIKit.h>



@interface ViewController : UIViewController <UIScrollViewDelegate>





@end

 

//

//  ViewController.m

//  UI2_ScrollView&UIPageControl

//

//  Created by zhangxueming on 15/7/10.

//  Copyright (c) 2015年 zhangxueming. All rights reserved.

//



#import "ViewController.h"



#define ClipsBundleWidth ((self.view.frame.size.width-300)/2)



@interface ViewController ()

{

    UIScrollView *_scrollView;

    UIPageControl *_pageControl;//页码

    NSInteger _currentIndex;//记录当前显示的页码

}

@end



@implementation ViewController



- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

    _scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(ClipsBundleWidth, 64, 300, 450)];

    _scrollView.contentSize = CGSizeMake(300*6, 450);

    _scrollView.pagingEnabled = YES;

    

    

    for (int i=0;  i<6; i++) {

        NSString *imageName = [NSString stringWithFormat:@"%d",i];

        NSString *path = [[NSBundle mainBundle] pathForResource:imageName ofType:@"png"];

        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(300*i, 0, 300, 450)];

        imageView.image = [UIImage imageWithContentsOfFile:path];

        [_scrollView addSubview:imageView];

    }

    

    _pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(ClipsBundleWidth, 64+450, 300, 30)];

    _pageControl.numberOfPages = 6;

    _currentIndex = 0;

    _pageControl.currentPage = _currentIndex;

    _pageControl.backgroundColor = [UIColor blackColor];

    

    [self.view addSubview:_pageControl];

    

    UIButton *backBtn = [UIButton buttonWithType:UIButtonTypeSystem];

    backBtn.frame = CGRectMake(50, 64+450+30, (self.view.frame.size.width-100)/2, 30);

    [backBtn setTitle:@"back" forState:UIControlStateNormal];

    backBtn.titleLabel.font = [UIFont boldSystemFontOfSize:24];

    [backBtn addTarget:self action:@selector(backBtnClicked) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:backBtn];

    

    UIButton *forwardBtn = [UIButton buttonWithType:UIButtonTypeSystem];

    forwardBtn.frame = CGRectMake(50+(self.view.frame.size.width-100)/2, 64+450+30, (self.view.frame.size.width-100)/2, 30);

    [forwardBtn setTitle:@"forward" forState:UIControlStateNormal];

    forwardBtn.titleLabel.font = [UIFont boldSystemFontOfSize:24];

    [forwardBtn addTarget:self action:@selector(forwardBtnClicked) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:forwardBtn];

    

    //代理

    _scrollView.delegate = self;

    

    [self.view addSubview:_scrollView];

    

}



- (void)backBtnClicked

{

    _currentIndex--;

    if (_currentIndex>=0) {

        CGPoint point = CGPointMake(_currentIndex*300   , _scrollView.contentOffset.y);

        [_scrollView setContentOffset:point animated:YES];

        _pageControl.currentPage = _currentIndex;

    }

    else

    {

        _currentIndex = 5;

        CGPoint point = CGPointMake(_currentIndex*300   , _scrollView.contentOffset.y);

        [_scrollView setContentOffset:point animated:YES];

        _pageControl.currentPage = _currentIndex;

    }

}



- (void)forwardBtnClicked

{

    _currentIndex++;

    if (_currentIndex<=5) {

        CGPoint point = CGPointMake(_currentIndex*300, _scrollView.contentOffset.y);

        [_scrollView setContentOffset:point animated:YES];

        _pageControl.currentPage = _currentIndex;

    }

    else

    {

        _currentIndex = 5;

    }

}



- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView

{

    _currentIndex = scrollView.contentOffset.x/300;

    _pageControl.currentPage = _currentIndex;

}



- (void)didReceiveMemoryWarning {

    [super didReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}



@end