IOS changes the system navigation bar's own return action event

#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

#import "Uiviewcontroller+backbuttonhandler.h"

@implementation Uiviewcontroller (Backbuttonhandler)

@end

@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

#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///write the event handling of the return button in this method

{

[Self.navigationcontroller Popviewcontrolleranimated:yes];

return YES;

}

IOS changes the system navigation bar's own return action event