改良UIScrollView滾動視圖

#define HEIGHT  self.view.frame.size.height

#define WIDTH    self.view.frame.size.width

 

@interface ViewController : UIViewController<UIScrollViewDelegate>

 

@property (strong,nonatomic) UIScrollView *myScorolV;

@property (strong,nonatomic) UIPageControl *pageC;

@property (strong,nonatomic) NSMutableArray *arrPage;

@property (strong,nonatomic) UIImageView *threeImage;

@property (strong,nonatomic) UIImageView *secondImage;

@property (strong,nonatomic) UIImageView *firstImage;

 @property (assign,nonatomic) int currentPage; 

 

@end

 

  

   //滾動視圖建立

    self.myScorolV = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, WIDTH, HEIGHT)];

    self.myScorolV.contentSize = CGSizeMake(WIDTH * 3, 0);

    self.myScorolV.pagingEnabled = YES;

    self.myScorolV.showsHorizontalScrollIndicator = NO;

    self.myScorolV.delegate = self;

  

    [self.view addSubview:self.myScorolV];

    

   //分頁視圖

    self.pageC = [[UIPageControl alloc] initWithFrame:CGRectMake(WIDTH / 5 * 2, HEIGHT - 80, WIDTH / 5, 40)];

    self.pageC.backgroundColor = [UIColor clearColor];

    self.pageC.currentPage = 0;

    self.pageC.numberOfPages = 5;

    //指定頁碼顏色

    self.pageC.currentPageIndicatorTintColor = [UIColor redColor];

    self.pageC.pageIndicatorTintColor = [UIColor greenColor];

    [self.view addSubview:self.pageC];

    

    self.arrPage = [NSMutableArray arrayWithCapacity:10];

    for (int i = 1; i < 6; i++)

    {

        UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"%d.png",i]];

        [self.arrPage addObject:image];

    }

    

    self.firstImage = [[UIImageView alloc] init];

    self.secondImage = [[UIImageView alloc] init];

    self.threeImage = [[UIImageView alloc] init];

    

    self.currentPage = 0;

    

    [self relodeImage];

    

}

 

-(void)relodeImage

{

    if (self.currentPage == 0)

    {

        self.firstImage.image = [self.arrPage lastObject];

        self.secondImage.image = [self.arrPage objectAtIndex:self.currentPage];

        self.threeImage.image = [self.arrPage objectAtIndex:self.currentPage + 1];

    }

    

    else if (self.currentPage == self.arrPage.count - 1)

    {

        self.firstImage.image = [self.arrPage objectAtIndex:self.currentPage - 1];

        self.secondImage.image = [self.arrPage objectAtIndex:self.currentPage];

        self.threeImage.image = [self.arrPage objectAtIndex:0];

    }

    

    else

    {

        self.firstImage.image = [self.arrPage objectAtIndex:self.currentPage - 1];

        self.secondImage.image = [self.arrPage objectAtIndex:self.currentPage];

        self.threeImage.image = [self.arrPage objectAtIndex:self.currentPage + 1];

    }

    

    

    self.firstImage.frame = CGRectMake(0, 0, WIDTH, HEIGHT);

    self.secondImage.frame = CGRectMake(WIDTH, 0, WIDTH, HEIGHT);

    self.threeImage.frame = CGRectMake(WIDTH * 2, 0, WIDTH, HEIGHT);

    

    [self.myScorolV addSubview:self.firstImage];

    [self.myScorolV addSubview:self.secondImage];

    [self.myScorolV addSubview:self.threeImage];

    

    self.myScorolV.contentOffset = CGPointMake(WIDTH, 0);

}

 

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView

{

    int number = (int)self.myScorolV.contentOffset.x;

    

    if (number < 0 || number == 0)

    {

        if (self.currentPage == 0)

        {

            self.currentPage = (int)(self.arrPage.count - 1);

        }

        

        else

        {

           self.currentPage--;

        }

    }

    

    else if (number > WIDTH * 2 || number == WIDTH * 2)

    {

        if (self.currentPage == (int)self.arrPage.count - 1)

        {

            self.currentPage = 0;

        }

        else

        {

            self.currentPage++;

        }

    }

    self.pageC.currentPage = self.currentPage;

    [self relodeImage];

    

}