简单的实现抽屉效果

.h文件
#import <UIKit/UIKit.h>
@interface MainViewController : UIViewController
+ (instancetype)mainViewControllerWithLeftViewController:(UIViewController *)leftViewController withMainPageViewController:(UIViewController *)mainPageViewController;
@end
.m文件
#import "MainViewController.h"
#define KWidth self.view.frame.size.width
#define KHeight self.view.frame.size.height
@interface MainViewController ()
@property (nonatomic,strong)UIViewController *leftVC;
@property (nonatomic,strong)UIViewController *centerVC;
@property (nonatomic,assign)BOOL isSlider;
@property (nonatomic,strong)UIView *corverView;
@end

 @implementation MainViewController
 + (instancetype)mainViewControllerWithLeftViewController:(UIViewController *)leftViewController withMainPageViewController:(UIViewController *)mainPageViewController{
MainViewController *mainVC = [[MainViewController alloc] init];
mainVC.leftVC = leftViewController;
mainVC.centerVC = mainPageViewController;
return mainVC;
 }
 - (void)viewDidLoad{
[super viewDidLoad];
self.isSlider = NO;
self.view.backgroundColor = [UIColor whiteColor];
[self addChildViewController:self.leftVC];
[self.view addSubview:self.leftVC.view];
[self addChildViewController:self.centerVC];
[self.view addSubview:self.centerVC.view];
// 给左视图和主视图添加手势
[self addGestureForView];
 }
 // 给主视图添加遮盖
 - (void)addCorverView{
if (self.corverView) {
    [self.corverView removeFromSuperview];
    self.corverView = nil;
}
self.corverView = [[UIView alloc] initWithFrame:self.centerVC.view.bounds];
_corverView.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.0];
[self.centerVC.view addSubview:self.corverView];
 }
 // 移除主视图遮盖
 - (void)removeCoverView{
if (self.corverView) {
    [self.corverView removeFromSuperview];
    self.corverView = nil;
}
 }
 // 给左视图和主视图添加手势
 - (void)addGestureForView{
UISwipeGestureRecognizer *rightGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeRightAction:)];
rightGesture.direction = UISwipeGestureRecognizerDirectionRight;
[self.centerVC.view addGestureRecognizer:rightGesture];
UISwipeGestureRecognizer *leftGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeLeftAction:)];
leftGesture.direction = UISwipeGestureRecognizerDirectionLeft;
[self.centerVC.view addGestureRecognizer:leftGesture];
UISwipeGestureRecognizer *leftVCLeftSwipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(leftVCLeftSwipeAction:)];
leftVCLeftSwipeGesture.direction = UISwipeGestureRecognizerDirectionLeft;
[self.leftVC.view addGestureRecognizer:leftVCLeftSwipeGesture];
 }
 - (void)swipeRightAction:(id)sender{
[self moveView:self.centerVC.view scale:0.8 panValue:KWidth];
self.isSlider = YES;
[self addCorverView];
 }
 - (void)swipeLeftAction:(id)sender{
[self moveView:self.centerVC.view scale:1 panValue:KWidth / 2];
self.isSlider = NO;
[self removeCoverView];
 }
 - (void)leftVCLeftSwipeAction:(id)sender{
[self moveView:self.centerVC.view scale:1 panValue:KWidth / 2];
self.isSlider = NO;
[self removeCoverView];
 }
 // 平移和缩放一个视图
 - (void)moveView:(UIView *)view scale:(CGFloat)scale panValue:(CGFloat)value{
[UIView beginAnimations:nil context:nil];
view.transform = CGAffineTransformScale(CGAffineTransformIdentity,scale,scale);
view.center = CGPointMake(value, view.center.y);
[UIView commitAnimations];
 }
 @end

在ViewController中调用

UIViewController *left = [[UIViewController alloc] init];
left.view.backgroundColor = [UIColor yellowColor];
UIViewController *right = [[UIViewController alloc] init];
right.view.backgroundColor = [UIColor redColor];
UIViewController *vc =  [MainViewController mainViewControllerWithLeftViewController:left withMainPageViewController:right];
[self addChildViewController:vc];
[self.view addSubview:vc.view];