在UIPageController中添加Pop返回手势

NSObject+FMAdd.m

//
//  NSObject+FMAdd.m
//  Followme
//
//  Created by Subo on 2018/3/22.
//  Copyright © 2018年 com.followme. All rights reserved.
//

#import "NSObject+FMAdd.h"

@implementation NSObject (FMAdd)

+ (void)fm_swizzleSelector:(SEL)originalSelector withSelector:(SEL)swizzledSelector {
    Class class = [self class];
    
    Method originalMethod = class_getInstanceMethod(class, originalSelector);
    Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
    
    BOOL success = class_addMethod(class, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod));
    if (success) {
        class_replaceMethod(class, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));
    }else {
        method_exchangeImplementations(originalMethod, swizzledMethod);
    }
}

@end

UIPageViewController使用的地方调用 enablePopGesture 方法

 #import "UIScrollView+FMAdd.h"

/**
 UIPageViewController中全局的pop手势会失效，这里通过这种设置开启
 */
- (void)enablePopGesture {
    for (UIView *view in self.pageViewController.view.subviews) {
        if ([view isKindOfClass:[UIScrollView class]]) {
            ((UIScrollView *)view).popGestureEnable = YES;
            break;
        }
    }
}

UIScrollView+FMAdd.m

//
//  UIScrollView+FMAdd.m
//  Followme
//
//  Created by Subo on 2018/3/22.
//  Copyright © 2018年 com.followme. All rights reserved.
//

#import "UIScrollView+FMAdd.h"
#import "NSObject+FMAdd.h"
#import <objc/runtime.h>

@implementation UIScrollView (FMAdd)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        [self fm_swizzleSelector:@selector(gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:)
                    withSelector:@selector(fm_gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:)];
    });
}

- (BOOL)fm_gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
    if (!self.popGestureEnable) {
        return [self fm_gestureRecognizer:gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:otherGestureRecognizer];
    }

    if (self.contentOffset.x + self.contentInset.left <= 0) {
        if ([otherGestureRecognizer.delegate isKindOfClass:NSClassFromString(@"_FDFullscreenPopGestureRecognizerDelegate")]) {
            return YES;
        }
    }
    return NO;
}

- (BOOL)popGestureEnable {
    NSNumber *number = objc_getAssociatedObject(self, @selector(popGestureEnable));
    return [number boolValue];
}


- (void)setPopGestureEnable:(BOOL)popGestureEnable {
    objc_setAssociatedObject(self, @selector(popGestureEnable), @(popGestureEnable), OBJC_ASSOCIATION_COPY_NONATOMIC);
}

@end