#import <UIKit/UIKit.h>#import "ViewController.h"//window窗口#define WINDOW  [[UIApplication sharedApplication]keyWindow]@interface MyNavigationViewController : UINavigationController@end

#define D_screenWidth 568#define D_leastOffset 50#import "MyNavigationViewController.h"#import <QuartzCore/QuartzCore.h>@interface MyNavigationViewController (){    CGPoint startTouch;//拖动时的开始坐标    BOOL isMoving;//是否在拖动中    UIView *blackMask;//那层黑面罩        UIImageView *lastScreenShotView;//截图}@property (nonatomic,retain) UIView *backgroundView;//背景@property (nonatomic,retain) NSMutableArray *screenShotsList;//存截图@end@implementation MyNavigationViewController- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        // 只少2个 头一个肯定是顶级的界面        self.screenShotsList = [[NSMutableArray alloc]initWithCapacity:2];    }    return self;}- (void)viewDidLoad{    [super viewDidLoad];    //拖动手势    UIPanGestureRecognizer *panGesture=[[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(handlePanGesture:)];    //添加手势    [self.view addGestureRecognizer:panGesture];        //是否开始拖动    isMoving = NO;    }//拖动手势-(IBAction)handlePanGesture:(UIGestureRecognizer*)sender{    //如果是顶级viewcontroller，结束    if (self.viewControllers.count <= 1) return;    //得到触摸中在window上拖动的过程中的xy坐标    CGPoint translation=[sender locationInView:WINDOW];    //状态结束，保存数据    if(sender.state == UIGestureRecognizerStateEnded){        NSLog(@"结束%f,%f",translation.x,translation.y);        isMoving = NO;        self.backgroundView.hidden = NO;        //如果结束坐标大于开始坐标D_leastOffset像素就动画效果移动        if (translation.x - startTouch.x > D_leastOffset) {            [UIView animateWithDuration:0.3 animations:^{                //动画效果，移动                [self moveViewWithX:D_screenWidth];            } completion:^(BOOL finished) {                //返回上一层                [self popViewControllerAnimated:NO];                //并且还原坐标                CGRect frame = self.view.frame;                frame.origin.x = 0;                self.view.frame = frame;            }];                    }else{            //不大于D_leastOffset时就移动原位            [UIView animateWithDuration:0.3 animations:^{                //动画效果                [self moveViewWithX:0];            } completion:^(BOOL finished) {                //背景隐藏                self.backgroundView.hidden = YES;            }];        }        return;            }else if(sender.state == UIGestureRecognizerStateBegan){        NSLog(@"开始%f,%f",translation.x,translation.y);        //开始坐标        startTouch = translation;        //是否开始移动        isMoving = YES;        if (!self.backgroundView)        {            //添加背景            CGRect frame = self.view.frame;            self.backgroundView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, frame.size.width , frame.size.height)];            //把backgroundView插入到Window视图上，并below低于self.view层            [WINDOW insertSubview:self.backgroundView belowSubview:self.view];                        //在backgroundView添加黑色的面罩            blackMask = [[UIView alloc]initWithFrame:CGRectMake(0, 0, frame.size.width , frame.size.height)];            blackMask.backgroundColor = [UIColor blackColor];            [self.backgroundView addSubview:blackMask];        }        self.backgroundView.hidden = NO;        if (lastScreenShotView) [lastScreenShotView removeFromSuperview];                //数组中最后截图        UIImage *lastScreenShot = [self.screenShotsList lastObject];        //并把截图插入到backgroundView上，并黑色的背景下面        lastScreenShotView = [[UIImageView alloc]initWithImage:lastScreenShot];        [self.backgroundView insertSubview:lastScreenShotView belowSubview:blackMask];            }        if (isMoving) {        [self moveViewWithX:translation.x - startTouch.x];    }}- (void)moveViewWithX:(float)x{        NSLog(@"Move to:%f",x);    x = x>D_screenWidth?D_screenWidth:x;    x = x<0?0:x;        CGRect frame = self.view.frame;    frame.origin.x = x;    self.view.frame = frame;       // float scale = (x/6400)+0.95;//缩放大小    float alpha = 0.4 - (x/(D_screenWidth *2));//透明值        //缩放scale    //lastScreenShotView.transform = CGAffineTransformMakeScale(scale, scale);    //背景颜色透明值    blackMask.alpha = alpha;    }//把UIView转化成UIImage，实现截屏- (UIImage *)ViewRenderImage{    //创建基于位图的图形上下文 Creates a bitmap-based graphics context with the specified options.:UIGraphicsBeginImageContextWithOptions(CGSize size, BOOL opaque, CGFloat scale),size大小，opaque是否透明，不透明（YES），scale比例缩放    UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, self.view.opaque, 0.0);       //当前层渲染到上下文    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];    //上下文形成图片    UIImage * img = UIGraphicsGetImageFromCurrentImageContext();    //结束并删除当前基于位图的图形上下文。    UIGraphicsEndImageContext();    //反回图片    return img;}#pragma Navagation 覆盖方法-(void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated{    //图像数组中存放一个当前的界面图像，然后再push    [self.screenShotsList addObject:[self ViewRenderImage]];    [super pushViewController:viewController animated:animated];}-(UIViewController *)popViewControllerAnimated:(BOOL)animated{    //移除最后一个    [self.screenShotsList removeLastObject];    return [super popViewControllerAnimated:animated];}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end