iOS覆盖系统返回按钮后，滑动返回功能

在开发中，我们一般会覆盖系统默认的导航栏上的返回按钮(修改按钮颜色和文字)。

具体做法如下：

// 创建按钮
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setTitle:@"返回" forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:@"navigationButtonReturn"] forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:@"navigationButtonReturnClick"] forState:UIControlStateHighlighted];
// 按钮自适应
[button sizeToFit];

// 让按钮的内容往左边偏移10
button.contentEdgeInsets = UIEdgeInsetsMake(0, -10, 0, 0);
[button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[button setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];

// 添加监听方法
[button addTarget:self action:@selector(backClick) forControlEvents:UIControlEventTouchUpInside];

// 修改导航栏左边的item
viewController.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:button];

创建一个

UIButton

，给这个按钮设置图片和标题，然后修改为

UIBarButtonItem

。



这样这个

返回按钮

就变成了我们想要的样子。

但是这种做法也伴随着一个问题：原本iOS系统的滑动返回功能失效了。



(只能点击 “返回按钮” 返回)

解决：

这个问题的根本是手势失效了。

可能1：手势被清空了

// self是我们自定义的导航控制器
NSLog(@"%@",self.interactivePopGestureRecognizer);

打印结果有手势，手势被清空的可能被排除：

<UIScreenEdgePanGestureRecognizer: 0x7fec5a7198a0; state = Possible; delaysTouchesBegan = YES; view = <UILayoutContainerView 0x7fec5a709080>; target= <(action=handleNavigationTransition:, target=<_UINavigationInteractiveTransition 0x7fec5a727ae0>)>>

可能2：手势代理做了一些事情，导致手势失效

1、控制器时态加载完成设置interactivePopGestureRecognizer的代理为控制本身

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.

// 手势代理
self.interactivePopGestureRecognizer.delegate = self;
}

2、当然在

@interface

就要继承代理协议了

@interface NavigationController () <UIGestureRecognizerDelegate>

@end

3、实现相关代理方法

#pragma mark - <UIGestureRecognizerDelegate>
/**
决定是否触发手势
*/
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
// 排除根控制器，其他所有子控制器都要触发手势
return self.childViewControllers.count > 1;
}

(这样iOS 7后系统默认的滑动返回功能也有了)

最后贴一下我们这个自定义导航控制的代码：

//
//  NavigationController.m

#import "NavigationController.h"

@interface NavigationController () <UIGestureRecognizerDelegate>

@end

@implementation NavigationController

+ (void)load
{
UINavigationBar *navBar = [UINavigationBar appearanceWhenContainedIn:self, nil];
[navBar setBackgroundImage:[UIImage imageNamed:@"navigationbarBackgroundWhite"] forBarMetrics:UIBarMetricsDefault];
}

#pragma mark - <UIGestureRecognizerDelegate>
/**
决定是否触发手势
*/
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
// 排除根控制器，其他所有子控制器都要触发手势
return self.childViewControllers.count > 1;
}

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.

// 手势代理
self.interactivePopGestureRecognizer.delegate = self;
}

/**
重写导航控制器的push方法
*/
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
// 在push之前，统一设计返回按钮
// 只有非根控制才需要设置
if (self.childViewControllers.count > 0) {

// 创建按钮
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setTitle:@"返回" forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:@"navigationButtonReturn"] forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:@"navigationButtonReturnClick"] forState:UIControlStateHighlighted];
// 按钮自适应
[button sizeToFit];

// 让按钮的内容往左边偏移10
button.contentEdgeInsets = UIEdgeInsetsMake(0, -10, 0, 0);
[button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[button setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];

// 添加监听方法
[button addTarget:self action:@selector(backClick) forControlEvents:UIControlEventTouchUpInside];

// 修改导航栏左边的item
viewController.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:button];

// 隐藏tabbar
viewController.hidesBottomBarWhenPushed = YES;
}

// 跳转
// 调用父类
[super pushViewController:viewController animated:animated];
}

- (void)backClick
{
// 导航控制器返回
[self popViewControllerAnimated:YES];
}

@end