iOS导航栏的按钮处理

转自：http://www.jianshu.com/p/e7c5e2400935

前言（其实就是废话，可以忽略 = =）

正文

UINavigationController

UINavigationController

@property

@property(nullable, nonatomic, readonly) UIGestureRecognizer *interactivePopGestureRecognizer

self.navigationController.interactivePopGestureRecognizer.enabled = YES;   //启用侧滑手势
self.navigationController.interactivePopGestureRecognizer.enabled = NO;   //禁用侧滑手势

UIBarButtonItem

navigationController

backBarButtonItem

backBarButtonItem

leftBarButtonItem

leftBarButtonItem

backBarButtonItem

leftBarButtonItem

UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
//对按钮的个性化设定

UIBarButtonItem *barItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
self.navigationItem.leftBarButtonItem = barItem; //侧滑手势失效
self.navigationItem.backBarButtonItem = barItem; //不影响侧滑手势

UINavigationController

BSDemoNavigationController

//首先先让我们自定义的 UINavigationController 遵守几个协议
@interface BSDemoNavigationController ()<UINavigationControllerDelegate,UIGestureRecognizerDelegate,BSNavigationBarButtonActionDelegate>

@property(nonatomic,weak) UIViewController* currentShowVC;

@end

@implementation BSDemoNavigationController

-(id)initWithRootViewController:(UIViewController *)rootViewController
{
//覆盖创建
BSDemoNavigationController* nvc = [super initWithRootViewController:rootViewController];
nav.interactivePopGestureRecognizer.delegate = self;
nvc.delegate = self;
return nvc;
}

#pragma mark - UIGestureRecognizerDelegate
//这个方法在视图控制器完成push的时候调用
-(void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
if (navigationController.viewControllers.count == 1){
//如果堆栈内的视图控制器数量为1 说明只有根控制器，将currentShowVC 清空，为了下面的方法禁用侧滑手势
self.currentShowVC = Nil;
}
else{
//将push进来的视图控制器赋值给currentShowVC
self.currentShowVC = viewController;
}
}
//这个方法是在手势将要激活前调用：返回YES允许侧滑手势的激活，返回NO不允许侧滑手势的激活
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
//首先在这确定是不是我们需要管理的侧滑返回手势
if (gestureRecognizer == self.interactivePopGestureRecognizer) {
if (self.currentShowVC == self.topViewController) {
//如果 currentShowVC 存在说明堆栈内的控制器数量大于 1 ，允许激活侧滑手势
return YES;
}
//如果 currentShowVC 不存在，禁用侧滑手势。如果在根控制器中不禁用侧滑手势，而且不小心触发了侧滑手势，会导致存放控制器的堆栈混乱，直接的效果就是你发现你的应用假死了，点哪都没反应，感兴趣是神马效果的朋友可以自己试试 = =。
return NO;
}

//这里就是非侧滑手势调用的方法啦，统一允许激活
return YES;
}

UINavigationController

UITabelView

UIScrollView

BSDemoNavigationController

//获取侧滑返回手势
- (UIScreenEdgePanGestureRecognizer *)screenEdgePanGestureRecognizer
{
UIScreenEdgePanGestureRecognizer *screenEdgePanGestureRecognizer = nil;
if (self.view.gestureRecognizers.count > 0)
{
for (UIGestureRecognizer *recognizer in self.view.gestureRecognizers)
{
if ([recognizer isKindOfClass:[UIScreenEdgePanGestureRecognizer class]])
{
screenEdgePanGestureRecognizer = (UIScreenEdgePanGestureRecognizer *)recognizer;
break;
}
}
}
return screenEdgePanGestureRecognizer;
}

BSDemoNavigationController

self.navigationController

self.navigationController

//禁止侧滑手势和tableView同时滑动
BSDemoNavigationController *navController = (BSDemoNavigationController *)self.navigationController;
if ([navController screenEdgePanGestureRecognizer]) {
//指定滑动手势在侧滑返回手势失效后响应
[self.friendsDemoTableView.panGestureRecognizer requireGestureRecognizerToFail:[navController screenEdgePanGestureRecognizer]];
}

更新

backBarButtonItem

backBarButtonItem

一、理解误区

backBarButtonItem

backIndicatorImage

backBarButtonItem

backIndicatorImage

backIndicatorImage

navigationBar

navigationController

backBarButtonItem

navigationItem

viewController

backBarButtonItem

leftBarButtonItem

rightBarButtonItem

backBarButtonItem

backBarButtonItem

backBarButtonItem

backBarButtonItem

二、情景实战

backBarButtonItem

- (void)viewDidLoad

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.navigationItem.title = @"Fir Controller";
self.navigationItem.leftItemsSupplementBackButton = YES;

UIButton  *button = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
[button setTitle:@"下一层" forState:UIControlStateNormal];
[button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[button addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];

UIBarButtonItem *backItem = [[UIBarButtonItem alloc]init];
backItem.title = @"A的BackButtonItem";
self.navigationItem.backBarButtonItem = backItem;
}

navigationController

- (void)viewDidLoad

#import "CustomNavigationController.h"

@implementation CustomNavigationController

- (instancetype)initWithRootViewController:(UIViewController *)rootViewController {
if (self = [super initWithRootViewController:rootViewController]) {
UIImage *image = [UIImage imageNamed:@"JWDemo_Back"];
image = [image imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
self.navigationBar.backIndicatorImage = image;
self.navigationBar.backIndicatorTransitionMaskImage = image;
}
return self;
}
@end

- (void)viewDidLoad

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.navigationItem.title = @"Fir Controller";
self.navigationItem.leftItemsSupplementBackButton = YES;

UIButton  *button = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
[button setTitle:@"下一层" forState:UIControlStateNormal];
[button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[button addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];

UIBarButtonItem *backItem = [[UIBarButtonItem alloc]init];
backItem.title = @"";
self.navigationItem.backBarButtonItem = backItem;
}