iOS侧滑返回

相关原理

iOS侧滑返回，有三种方案可以实现（只考虑iOS7以后）

• 开启使用系统自带的侧滑返回

  self.navigationController.interactivePopGestureRecognizer.enabled = YES;
  

• 实现UINavigationViewController的代理方法，自定义动画对象和交互对象（即自定义转场动画）

  有关的协议，有空研究下
  UIViewControllerAnimatedTransitioning：遵从该协议的对象，即是我们自定义的动画；
  UIViewControllerInteractiveTransitioning：遵从该协议实现动画可交互性。
  不过一般我们直接使用系统UIPercentDrivenInteractiveTransition类，不需自定义。
  UIViewControllerContextTransitioning：遵从该协议，定义了转场时需要的元数据。一般不需自己定义。
  

• 利用系统自带的侧滑返回，替换掉系统自带的侧滑手势的委托对象
  替换掉系统自带的侧滑手势的委托对象

  self.interactivePopGestureRecognizer.delegate = self;
  

  手势的代理方法

  #pragma mark - UIGestureRecognizerDelegate
  // 手势的代理方法
  - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:  (UITouch *)touch {
      BOOL isShould = NO;
      if ( (self.childViewControllers.count<=1) ) {
          isShould = NO;
      }else {
          isShould = YES;
      }
      return isShould;
  }
  

我的实践

1.QqcNavigationController继承自UINavigationController，替换系统侧滑手势的委托对象
QqcNavigationController.h

#import 

@interface QqcNavigationController : UINavigationController

//是否开启滑动退场
@property(nonatomic, assign)BOOL isPanBackGestureEnable;

@end

QqcNavigationController.m

#import "QqcNavigationController.h"

@interface QqcNavigationController ()

@end

@implementation QqcNavigationController

#pragma mark - system framwork
- (void)viewDidLoad {
    [super viewDidLoad];
    self.interactivePopGestureRecognizer.delegate = self;
}

#pragma mark - property
- (void)setIsPanBackGestureEnable:(BOOL)isPanBackGestureEnable {
    _isPanBackGestureEnable = isPanBackGestureEnable;
    self.interactivePopGestureRecognizer.enabled = _isPanBackGestureEnable;
}

#pragma mark - UIGestureRecognizerDelegate
// 手势的代理方法
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
    BOOL isShould = NO;
    if ( (self.childViewControllers.count<=1) ) {
        isShould = NO;
    }else {
        isShould = YES;
    }
    return isShould;
}

@end

2.在BaseViewController中当viewDidDisappear时禁用，viewDidAppear时根据情况禁用或开启
BaseViewController.h

#import "QqcBaseViewController.h"

@interface BaseViewController : QqcBaseViewController

#pragma mark - polymorphy
//是否需要滑动退场
- (BOOL)isPanBackGestureEnable;

@end

BaseViewController.m

#import "BaseViewController.h"
#import "QqcNavigationController.h"

@implementation BaseViewController

#pragma mark - polymorphy
//是否需要全屏滑动退场
- (BOOL)isPanBackGestureEnable {
    return YES;
}

#pragma mark - system framework
- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    //是否启用全屏滑动手势
    BOOL isPanBackEnable = [self isPanBackGestureEnable];
    ((QqcNavigationController*)self.navigationController).isPanBackGestureEnable = isPanBackEnable;
}

- (void)viewDidDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];
    //启用全屏滑动手势
    ((QqcNavigationController*)self.navigationController).isPanBackGestureEnable = NO;
}

@end

3.在SomeoneViewController中定制是否需要滑动返回手势

//是否需要滑动退场
- (BOOL)isPanBackGestureEnable {
    return NO;
}