iOS UIPageControl使用

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UIScrollViewDelegate>
{
UIScrollView* helpScrView;
UIPageControl* pageCtrl;
}
@end

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];
CGRect bounds = self.view.frame;  //获取界面区域

//加载蒙板图片，限于篇幅，这里仅显示一张图片的加载方法
UIImageView* imageView1 = [[[UIImageView alloc] initWithFrame:CGRectMake(0, bounds.origin.y, bounds.size.width, bounds.size.height)] autorelease];  //创建UIImageView，位置大小与主界面一样。
[imageView1 setImage:[UIImage imageNamed:@"bg.png"]];  //加载图片help01.png到imageView1中。
//imageView1.alpha = 0.5f;  //将透明度设为50%。
UIImageView* imageView2 = [[[UIImageView alloc] initWithFrame:CGRectMake(1*bounds.size.width, bounds.origin.y, bounds.size.width, bounds.size.height)] autorelease];  //创建UIImageView，位置大小与主界面一样。
[imageView2 setImage:[UIImage imageNamed:@"bg.png"]];
//继续加载图片
//。。。。

//创建UIScrollView
helpScrView = [[UIScrollView alloc] initWithFrame:CGRectMake(bounds.origin.x, bounds.origin.y, bounds.size.width, 300)];  //创建UIScrollView，位置大小与主界面一样。
[helpScrView setContentSize:CGSizeMake(bounds.size.width * 6, 300)];  //设置全部内容的尺寸，这里帮助图片是3张，所以宽度设为界面宽度*3，高度和界面一致。
helpScrView.pagingEnabled = YES;  //设为YES时，会按页滑动
helpScrView.bounces = NO; //取消UIScrollView的弹性属性，这个可以按个人喜好来定
[helpScrView setDelegate:self];//UIScrollView的delegate函数在本类中定义
helpScrView.showsHorizontalScrollIndicator = NO;  //因为我们使用UIPageControl表示页面进度，所以取消UIScrollView自己的进度条。
[helpScrView addSubview:imageView2];
[helpScrView addSubview:imageView1];//将UIImageView添加到UIScrollView中。
[self.view addSubview:helpScrView]; //将UIScrollView添加到主界面上。

//创建UIPageControl
pageCtrl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 400, bounds.size.width, 30)];  //创建UIPageControl，位置在屏幕最下方。
pageCtrl.numberOfPages = 6;//总的图片页数
pageCtrl.currentPage = 0; //当前页
[pageCtrl addTarget:self action:@selector(pageTurn:) forControlEvents:UIControlEventValueChanged];  //用户点击UIPageControl的响应函数
[self.view addSubview:pageCtrl];  //将UIPageControl添加到主界面上。
}

//其次是UIScrollViewDelegate的scrollViewDidEndDecelerating函数，用户滑动页面停下后调用该函数。

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
//更新UIPageControl的当前页
CGPoint offset = scrollView.contentOffset;
CGRect bounds = scrollView.frame;
[pageCtrl setCurrentPage:offset.x / bounds.size.width];
NSLog(@"%f",offset.x / bounds.size.width);
}

//然后是点击UIPageControl时的响应函数pageTurn

- (void)pageTurn:(UIPageControl*)sender
{
//令UIScrollView做出相应的滑动显示
CGSize viewSize = helpScrView.frame.size;
CGRect rect = CGRectMake(sender.currentPage * viewSize.width, 0, viewSize.width, viewSize.height);
[helpScrView scrollRectToVisible:rect animated:YES];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end

//
//  GrayPageControl.h
//  iPlayer
//
//  Created by 屎壳郎情调 on 13-9-11.
//  Copyright (c) 2013年 ibokan. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface GrayPageControl : UIPageControl
{
UIImage* activeImage;
UIImage* inactiveImage;
}
@end

//
//  GrayPageControl.m
//  iPlayer
//
//  Created by 屎壳郎情调 on 13-9-11.
//  Copyright (c) 2013年 ibokan. All rights reserved.
//

#import "GrayPageControl.h"

@implementation GrayPageControl

-(id) initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];

activeImage = [UIImage imageNamed:@"appleDot@2x"];
inactiveImage = [UIImage imageNamed:@"pageDot@2x"] ;

return self;
}

-(void) updateDots
{
for (int i = 0; i < [self.subviews count]; i++)
{
UIImageView* dot = [self.subviews objectAtIndex:i];
if (i == self.currentPage) dot.image = activeImage;
else dot.image = inactiveImage;
}
}

-(void) setCurrentPage:(NSInteger)page
{
[super setCurrentPage:page];
//修改图标大小
for (NSUInteger subviewIndex = 0; subviewIndex < [self.subviews count]; subviewIndex++) {

UIImageView* subview = [self.subviews objectAtIndex:subviewIndex];

CGSize size;

size.height = 10;

size.width = 10;

[subview setFrame:CGRectMake(subview.frame.origin.x, subview.frame.origin.y,

size.width,size.height)];

}

[self updateDots];
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// Drawing code
}
*/

@end