1.擴展UIviewController
UIViewController+BackButtonHandler.h

#import <UIKit/UIKit.h> @protocol BackButtonHandlerProtocol <NSObject> @optional // Override this method in UIViewController derived class to handle 'Back' button click -(BOOL)navigationShouldPopOnBackButton; @end @interface UIViewController (BackButtonHandler) <BackButtonHandlerProtocol> @end

UIViewController+BackButtonHandler.m文件

#import "UIViewController+BackButtonHandler.h"@implementation UIViewController (BackButtonHandler) @end

2.擴展UINavigationController ,也可以繼承 使用

@implementation UINavigationController (ShouldPopOnBackButton) - (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPopItem:(UINavigationItem*)item { if([self.viewControllers count] < [navigationBar.items count]) { return YES; } BOOL shouldPop = YES; UIViewController* vc = [self topViewController]; if([vc respondsToSelector:@selector(navigationShouldPopOnBackButton)]) { shouldPop = [vc navigationShouldPopOnBackButton]; } if(shouldPop) { dispatch_async(dispatch_get_main_queue(), ^{ [self popViewControllerAnimated:YES]; }); } else { // Workaround for iOS7.1. Thanks to @boliva - http://stackoverflow.com/posts/comments /34452906 for(UIView *subview in [navigationBar subviews]) { if(subview.alpha < 1.) { [UIView animateWithDuration:.25 animations:^{ subview.alpha = 1.; }]; } } } return NO; } @end

3.測試使用

#import "ViewController.h #import "UIViewController+BackButtonHandler.h"@implementation ViewController -(void) viewDidLoad { [super viewDidLoad]; self.title = [NSString stringWithFormat:@"Screen-%d", self.navigationController.viewControllers.count]; self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Next" style:UIBarButtonItemStylePlain target:selfaction:@selector(onNextBtn:)]; } -(void) onNextBtn:(id)sender { [self.navigationController pushViewController:[ViewController new] animated:YES]; } -(BOOL) navigationShouldPopOnBackButton ///在這個方法里寫返回按鈕的事件處理 { //這里寫要處理的代碼 [self.navigationController popViewControllerAnimated:YES]; return YES;//返回NO 不會執行 }

總結

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