maskView遮罩中多张图片的动画

//
//  ViewController.m
//  FeedBack
//
//  Created by YouXianMing on 15/5/6.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//

#import "ViewController.h"
#import "UIView+SetRect.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    
    // 前景图
    UIImageView *background = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
    background.image        = [UIImage imageNamed:@"base"];
    background.center       = self.view.center;
    [self.view addSubview:background];
    
    
    // 背景图
    UIImageView *upGround = [[UIImageView alloc] initWithFrame:background.frame];
    upGround.image        = [UIImage imageNamed:@"background"];
    [self.view addSubview:upGround];
    
    
    // maskView
    UIView *mask      = [[UIView alloc] initWithFrame:upGround.bounds];
    upGround.maskView = mask;
    
    
    // 图片1
    UIImageView *picOne = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 100, 400)];
    picOne.image        = [UIImage imageNamed:@"1"];
    [mask addSubview:picOne];
    
    
    // 图片2
    UIImageView *picTwo = [[UIImageView alloc] initWithFrame:CGRectMake(100, -200, 100, 400)];
    picTwo.image        = [UIImage imageNamed:@"2"];
    [mask addSubview:picTwo];
    
    
    // 动画
    [UIView animateWithDuration:4.f delay:5.f options:0 animations:^{
        picOne.y -= 400;
        picTwo.y += 400;
    } completion:^(BOOL finished) {
        
    }];
}

@end

//
//  UIView+SetRect.h
//  TestPch
//
//  Created by YouXianMing on 14-9-26.
//  Copyright (c) 2014年 YouXianMing. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIView (SetRect)

// Frame
@property (nonatomic) CGPoint viewOrigin;
@property (nonatomic) CGSize  viewSize;

// Frame Origin
@property (nonatomic) CGFloat x;
@property (nonatomic) CGFloat y;

// Frame Size
@property (nonatomic) CGFloat width;
@property (nonatomic) CGFloat height;

// Frame Borders
@property (nonatomic) CGFloat top;
@property (nonatomic) CGFloat left;
@property (nonatomic) CGFloat bottom;
@property (nonatomic) CGFloat right;

// Center Point
#if !IS_IOS_DEVICE
@property (nonatomic) CGPoint center;
#endif
@property (nonatomic) CGFloat centerX;
@property (nonatomic) CGFloat centerY;

// Middle Point
@property (nonatomic, readonly) CGPoint middlePoint;
@property (nonatomic, readonly) CGFloat middleX;
@property (nonatomic, readonly) CGFloat middleY;
@end

//
//  UIView+SetRect.m
//  TestPch
//
//  Created by YouXianMing on 14-9-26.
//  Copyright (c) 2014年 YouXianMing. All rights reserved.
//

#import "UIView+SetRect.h"

@implementation UIView (SetRect)

#pragma mark Frame

- (CGPoint)viewOrigin
{
    return self.frame.origin;
}

- (void)setViewOrigin:(CGPoint)newOrigin
{
    CGRect newFrame = self.frame;
    newFrame.origin = newOrigin;
    self.frame = newFrame;
}

- (CGSize)viewSize
{
    return self.frame.size;
}

- (void)setViewSize:(CGSize)newSize
{
    CGRect newFrame = self.frame;
    newFrame.size = newSize;
    self.frame = newFrame;
}


#pragma mark Frame Origin

- (CGFloat)x
{
    return self.frame.origin.x;
}

- (void)setX:(CGFloat)newX
{
    CGRect newFrame = self.frame;
    newFrame.origin.x = newX;
    self.frame = newFrame;
}

- (CGFloat)y
{
    return self.frame.origin.y;
}

- (void)setY:(CGFloat)newY
{
    CGRect newFrame = self.frame;
    newFrame.origin.y = newY;
    self.frame = newFrame;
}


#pragma mark Frame Size

- (CGFloat)height
{
    return self.frame.size.height;
}

- (void)setHeight:(CGFloat)newHeight
{
    CGRect newFrame = self.frame;
    newFrame.size.height = newHeight;
    self.frame = newFrame;
}

- (CGFloat)width
{
    return self.frame.size.width;
}

- (void)setWidth:(CGFloat)newWidth
{
    CGRect newFrame = self.frame;
    newFrame.size.width = newWidth;
    self.frame = newFrame;
}


#pragma mark Frame Borders

- (CGFloat)left
{
    return self.x;
}

- (void)setLeft:(CGFloat)left
{
    self.x = left;
}

- (CGFloat)right
{
    return self.frame.origin.x + self.frame.size.width;
}

- (void)setRight:(CGFloat)right
{
    self.x = right - self.width;
}

- (CGFloat)top
{
    return self.y;
}

- (void)setTop:(CGFloat)top
{
    self.y = top;
}

- (CGFloat)bottom
{
    return self.frame.origin.y + self.frame.size.height;
}

- (void)setBottom:(CGFloat)bottom
{
    self.y = bottom - self.height;
}


#pragma mark Center Point

#if !IS_IOS_DEVICE
- (CGPoint)center
{
    return CGPointMake(self.left + self.middleX, self.top + self.middleY);
}

- (void)setCenter:(CGPoint)newCenter
{
    self.left = newCenter.x - self.middleX;
    self.top = newCenter.y - self.middleY;
}
#endif

- (CGFloat)centerX
{
    return self.center.x;
}

- (void)setCenterX:(CGFloat)newCenterX
{
    self.center = CGPointMake(newCenterX, self.center.y);
}

- (CGFloat)centerY
{
    return self.center.y;
}

- (void)setCenterY:(CGFloat)newCenterY
{
    self.center = CGPointMake(self.center.x, newCenterY);
}


#pragma mark Middle Point

- (CGPoint)middlePoint
{
    return CGPointMake(self.middleX, self.middleY);
}

- (CGFloat)middleX
{
    return self.width / 2;
}

- (CGFloat)middleY
{
    return self.height / 2;
}

@end