//

//  MoreInfoView.h

//  YXCell

//

//  Copyright (c) 2014年 Y.X. All rights reserved.

//

#import <UIKit/UIKit.h>

@interface MoreInfoView : UIView

@property (nonatomic, strong) UIImageView *imageView;

@end

//

//  MoreInfoView.m

//  YXCell

//

//  Copyright (c) 2014年 Y.X. All rights reserved.

//

#import "MoreInfoView.h"

@implementation MoreInfoView

- (id)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self)

    {

        CGRect rect = frame;

        self.layer.borderWidth = 0.5f;

        self.layer.borderColor = [UIColor blackColor].CGColor;

        self.layer.masksToBounds = YES;

        _imageView = [[UIImageView alloc] initWithFrame:CGRectMake(-, ,

                                                                   rect.size.width + *,

                                                                   rect.size.height)];

        [self addSubview:_imageView];

    }

    return self;

}

@end

//

//  RootViewController.m

//  YXCell

//

//  Copyright (c) 2014年 Y.X. All rights reserved.

//

#import "RootViewController.h"

#import "MoreInfoView.h"

@interface RootViewController ()<UIScrollViewDelegate>

@property (nonatomic, strong) UIScrollView  *scrollView;

@property (nonatomic, assign) CGFloat        k;

@property (nonatomic, assign) CGFloat        b;

@end

@implementation RootViewController

- (void)linearFunctionPointA:(CGPoint)pointA

                      pointB:(CGPoint)pointB

{

    CGFloat x1 = pointA.x; CGFloat y1 = pointA.y;

    CGFloat x2 = pointB.x; CGFloat y2 = pointB.y;

    _k = calculateSlope(x1, y1, x2, y2);

    _b = calculateConstant(x1, y1, x2, y2);

}

- (void)viewDidLoad

{

    [super viewDidLoad];

    self.view.backgroundColor = [UIColor blackColor];

    // 计算斜率

    [self linearFunctionPointA:CGPointMake(, -)

                        pointB:CGPointMake(, )];

    _scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];

    _scrollView.delegate      = self;

    _scrollView.pagingEnabled = YES;

    [self.view addSubview:_scrollView];

    NSArray *picArray = @[[UIImage imageNamed:@""],

                          [UIImage imageNamed:@""],

                          [UIImage imageNamed:@""],

                          [UIImage imageNamed:@""],

                          [UIImage imageNamed:@""]];

    [picArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

        MoreInfoView *show = \

        [[MoreInfoView alloc] initWithFrame:CGRectMake(idx*self.view.bounds.size.width, ,

                                                       self.view.bounds.size.width,

                                                       self.view.bounds.size.height)];

        show.imageView.image = obj;

        [_scrollView addSubview:show];

    }];

    _scrollView.contentSize = CGSizeMake(picArray.count*self.view.bounds.size.width,

                                         self.view.bounds.size.height);

}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView

{

    CGFloat X = scrollView.contentOffset.x;

    [scrollView.subviews enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

        MoreInfoView *tmp = obj;

        if ([tmp isKindOfClass:[MoreInfoView class]])

        {

            // 产生视差效果

            CGRect rect = tmp.imageView.frame;

            rect.origin.x = _k * (X - idx*) + _b;

            tmp.imageView.frame = rect;

        }

    }];

}

// 计算用

CGFloat calculateSlope(CGFloat x1, CGFloat y1, CGFloat x2, CGFloat y2)

{

    return (y2 - y1) / (x2 - x1);

}

CGFloat calculateConstant(CGFloat x1, CGFloat y1, CGFloat x2, CGFloat y2)

{

    return (y1*(x2 - x1) - x1*(y2 - y1)) / (x2 - x1);

}

@end