抽屉效果

////  ViewController.m#import "ViewController.h"// 获取屏幕的宽度#define screenW  [UIScreen mainScreen].bounds.size.width@interface ViewController ()@property(nonatomic,weak)UIView *leftV;@property(nonatomic,weak)UIView *rightV;@property(nonatomic,weak)UIView *mainV;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];        // 添加子控件    [self createChildView];        // 添加pan手势    UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];    [self.view addGestureRecognizer:panRecognizer];        // 添加tap手势    UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap)];    [self.view addGestureRecognizer:tapRecognizer];}#pragma mark - tap的方法- (void)tap{    if (self.mainV.frame.origin.x != 0) {        [UIView animateWithDuration:0.25 animations:^{            self.mainV.frame = self.view.bounds;        }];    }}#pragma mark - pan的方法- (void)pan:(UIPanGestureRecognizer *)recognizer{    // 获取手势移动的位置    CGPoint point = [recognizer translationInView:self.view];        // 获取X轴心偏移量    CGFloat offsetX = point.x;        // 修改mainV的frame    self.mainV.frame = [self frameWithOffsetX:offsetX];        // 判断mainV的x是否大于0    if (self.mainV.frame.origin.x > 0) { // 往右边滑动，隐藏rightV        self.rightV.hidden = YES;    }else if (self.mainV.frame.origin.x < 0){ // 往左边滑动，显示rightV        self.rightV.hidden = NO;    }        // 复位    [recognizer setTranslation:CGPointZero inView:self.view];        // 判断当手势结束的时候，定位    if (recognizer.state == UIGestureRecognizerStateEnded) {        //  定位点        CGFloat target = 0;                if (self.mainV.frame.origin.x > screenW * 0.5) {            // 定位到右边            target = 220;        }else if (CGRectGetMaxX(self.mainV.frame) < screenW * 0.5 ){            target = -200;        }                // 获取X轴偏移量        CGFloat offsetX = target - self.mainV.frame.origin.x;                // 动画改变frame        [UIView animateWithDuration:0.25 animations:^{           self.mainV.frame = target == 0 ? self.view.bounds : [self frameWithOffsetX:offsetX];        }];    }}/** *  根据offsetX计算mainV的frame */#define kMaxY 80- (CGRect)frameWithOffsetX:(CGFloat)offsetX{    /*     手指往右移动，视图X轴也要往右移动(x++)     同时Y轴向下移动(y++)，尺寸缩放(按比例)     */        // 获取上一次的frame    CGRect frame = self.mainV.frame;    // 获取上一次的高度    CGFloat preH = frame.size.height;    // 获取上一次的宽度    CGFloat preW = frame.size.width;        // 获取屏幕的高度    CGFloat screenH = [UIScreen mainScreen].bounds.size.height;        // X轴每平移一点，Y轴需要移动    CGFloat offsetY = offsetX * kMaxY / screenW;        // 获取当前的高度    CGFloat currentH = frame.size.height - offsetY * 2;    if (frame.origin.x < 0) { // 往左边滑动        currentH = frame.size.height + offsetY * 2;    }        // 获取尺寸的缩放比例    CGFloat scale = currentH / preH;        // 获取当前的宽度    CGFloat currentW = preW * scale;        // 计算x    frame.origin.x += offsetX;    // 计算y    frame.origin.y = (screenH - currentH) / 2;        frame.size.height = currentH;    frame.size.width = currentW;        return frame;}#pragma mark - 添加子控件/** *  创建子控件 */- (void)createChildView{    UIView *leftV = [[UIView alloc] initWithFrame:self.view.bounds];    leftV.backgroundColor = [UIColor orangeColor];    [self.view addSubview:leftV];    self.leftV = leftV;        UIView *rightV = [[UIView alloc] initWithFrame:self.view.bounds];    rightV.backgroundColor = [UIColor blueColor];    [self.view addSubview:rightV];    self.rightV = rightV;        UIView *mainV = [[UIView alloc] initWithFrame:self.view.bounds];    mainV.backgroundColor = [UIColor redColor];    [self.view addSubview:mainV];    self.mainV = mainV;}@end

演示：