ios - Controlador de finalización para UINavigationController "pushViewController: animado"?

handler

Question

Estoy a punto de crear una aplicación usando un UINavigationController para presentar los siguientes controladores de vista. Con iOS5 hay un nuevo método para presentar UIViewControllers :

presentViewController:animated:completion:

Ahora me pregunto por qué no hay un controlador de finalización para UINavigationController ? Solo hay

pushViewController:animated:

¿Es posible crear mi propio controlador de finalización como el nuevo presentViewController:animated:completion: :?

Answer 1

Actualmente el UINavigationController no es compatible con esto. Pero está el UINavigationControllerDelegate que puede usar.

Una manera fácil de lograr esto es subclasificando UINavigationController y agregando una propiedad de bloque de terminación:

@interface PbNavigationController : UINavigationController <UINavigationControllerDelegate>
@property (nonatomic,copy) dispatch_block_t completionBlock;
@end
@implementation PbNavigationController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
self.delegate = self;
}
return self;
}
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
NSLog(@"didShowViewController:%@", viewController);
if (self.completionBlock) {
self.completionBlock();
self.completionBlock = nil;
}
}
@end

Antes de presionar el nuevo controlador de vista, debe establecer el bloque de finalización:

UIViewController *vc = ...;
((PbNavigationController *)self.navigationController).completionBlock = ^ {
NSLog(@"COMPLETED");
};
[self.navigationController pushViewController:vc animated:YES];

Esta nueva subclase se puede asignar en Interface Builder o se puede utilizar mediante programación de esta manera:

PbNavigationController *nc = [[PbNavigationController alloc]initWithRootViewController:yourRootViewController];

Answer 2

Aquí está la versión Swift 4 con el Pop.

extension UINavigationController {
public func pushViewController(viewController: UIViewController,
animated: Bool,
completion: (() -> Void)?) {
CATransaction.begin()
CATransaction.setCompletionBlock(completion)
pushViewController(viewController, animated: animated)
CATransaction.commit()
}
public func popViewController(animated: Bool,
completion: (() -> Void)?) {
CATransaction.begin()
CATransaction.setCompletionBlock(completion)
popViewController(animated: animated)
CATransaction.commit()
}
}

Solo en caso de que alguien más necesitara esto.

Answer 3

Basado en la respuesta de par (que era la única que funcionaba con iOS9), pero más simple y con un elemento faltante (lo que podría haber llevado a que nunca se llamara a la finalización):

extension UINavigationController {
func pushViewController(_ viewController: UIViewController, animated: Bool, completion: @escaping () -> Void) {
pushViewController(viewController, animated: animated)
if animated, let coordinator = transitionCoordinator {
coordinator.animate(alongsideTransition: nil) { _ in
completion()
}
} else {
completion()
}
}
func popViewController(animated: Bool, completion: @escaping () -> Void) {
popViewController(animated: animated)
if animated, let coordinator = transitionCoordinator {
coordinator.animate(alongsideTransition: nil) { _ in
completion()
}
} else {
completion()
}
}
}

Answer 4

Desde iOS 7.0, puede usar UIViewControllerTransitionCoordinator para agregar un bloque de finalización de inserción:

UINavigationController *nav = self.navigationController;
[nav pushViewController:vc animated:YES];
id<UIViewControllerTransitionCoordinator> coordinator = vc.transitionCoordinator;
[coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> _Nonnull context) {
} completion:^(id<UIViewControllerTransitionCoordinatorContext> _Nonnull context) {
NSLog(@"push completed");
}];

Answer 5

Para ampliar la respuesta de @Klaas (y como resultado de this pregunta) he agregado bloques de finalización directamente al método push:

@interface PbNavigationController : UINavigationController <UINavigationControllerDelegate>
@property (nonatomic,copy) dispatch_block_t completionBlock;
@property (nonatomic,strong) UIViewController * pushedVC;
@end
@implementation PbNavigationController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
self.delegate = self;
}
return self;
}
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
NSLog(@"didShowViewController:%@", viewController);
if (self.completionBlock && self.pushedVC == viewController) {
self.completionBlock();
}
self.completionBlock = nil;
self.pushedVC = nil;
}
-(void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
if (self.pushedVC != viewController) {
self.pushedVC = nil;
self.completionBlock = nil;
}
}
-(void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated completion:(dispatch_block_t)completion {
self.pushedVC = viewController;
self.completionBlock = completion;
[self pushViewController:viewController animated:animated];
}
@end

Para ser utilizado de la siguiente manera:

UIViewController *vc = ...;
[(PbNavigationController *)self.navigationController pushViewController:vc animated:YES completion:^ {
NSLog(@"COMPLETED");
}];

Answer 6

Se necesita un poco más de tuberías para agregar este comportamiento y conservar la capacidad de establecer un delegado externo.

Aquí hay una implementación documentada que mantiene la funcionalidad de delegado:

LBXCompletingNavigationController

Answer 7

Swift 2.0

extension UINavigationController : UINavigationControllerDelegate {
private struct AssociatedKeys {
static var currentCompletioObjectHandle = "currentCompletioObjectHandle"
}
typealias Completion = @convention(block) (UIViewController)->()
var completionBlock:Completion?{
get{
let chBlock = unsafeBitCast(objc_getAssociatedObject(self, &AssociatedKeys.currentCompletioObjectHandle), Completion.self)
return chBlock as Completion
}set{
if let newValue = newValue {
let newValueObj : AnyObject = unsafeBitCast(newValue, AnyObject.self)
objc_setAssociatedObject(self, &AssociatedKeys.currentCompletioObjectHandle, newValueObj, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
}
}
}
func popToViewController(animated: Bool,comp:Completion){
if (self.delegate == nil){
self.delegate = self
}
completionBlock = comp
self.popViewControllerAnimated(true)
}
func pushViewController(viewController: UIViewController, comp:Completion) {
if (self.delegate == nil){
self.delegate = self
}
completionBlock = comp
self.pushViewController(viewController, animated: true)
}
public func navigationController(navigationController: UINavigationController, didShowViewController viewController: UIViewController, animated: Bool){
if let comp = completionBlock{
comp(viewController)
completionBlock = nil
self.delegate = nil
}
}
}

Answer 8

iOS 7+ Swift

EDITAR: He agregado una versión de Swift 3 de mi respuesta original. En esta versión eliminé la co-animación de ejemplo que se muestra en la versión de Swift 2, ya que parece haber confundido a muchas personas.

Swift 3:

import UIKit
// Swift 3 version, no co-animation (alongsideTransition parameter is nil)
extension UINavigationController {
public func pushViewController(
_ viewController: UIViewController,
animated: Bool,
completion: @escaping (Void) -> Void)
{
pushViewController(viewController, animated: animated)
guard animated, let coordinator = transitionCoordinator else {
completion()
return
}
coordinator.animate(alongsideTransition: nil) { _ in completion() }
}
}

Swift 2:

import UIKit
// Swift 2 Version, shows example co-animation (status bar update)
extension UINavigationController {
public func pushViewController(
viewController: UIViewController,
animated: Bool,
completion: Void -> Void)
{
pushViewController(viewController, animated: animated)
guard animated, let coordinator = transitionCoordinator() else {
completion()
return
}
coordinator.animateAlongsideTransition(
// pass nil here or do something animated if you''d like, e.g.:
{ context in
viewController.setNeedsStatusBarAppearanceUpdate()
},
completion: { context in
completion()
}
)
}
}

Answer 9

Vea la respuesta de par para otra solución más actualizada

UINavigationController animaciones de UINavigationController se ejecutan con CoreAnimation , por lo que tendría sentido encapsular el código dentro de CATransaction y así establecer un bloque de finalización.

Swift :

Para swift, sugiero crear una extensión como tal

extension UINavigationController {
public func pushViewController(viewController: UIViewController,
animated: Bool,
completion: @escaping (() -> Void)?) {
CATransaction.begin()
CATransaction.setCompletionBlock(completion)
pushViewController(viewController, animated: animated)
CATransaction.commit()
}
}

Uso:

navigationController?.pushViewController(vc, animated: true) {
// Animation done
}

C objetivo

Encabezamiento:

#import <UIKit/UIKit.h>
@interface UINavigationController (CompletionHandler)
- (void)completionhandler_pushViewController:(UIViewController *)viewController
animated:(BOOL)animated
completion:(void (^)(void))completion;
@end

Implementación:

#import "UINavigationController+CompletionHandler.h"
#import <QuartzCore/QuartzCore.h>
@implementation UINavigationController (CompletionHandler)
- (void)completionhandler_pushViewController:(UIViewController *)viewController
animated:(BOOL)animated
completion:(void (^)(void))completion
{
[CATransaction begin];
[CATransaction setCompletionBlock:completion];
[self pushViewController:viewController animated:animated];
[CATransaction commit];
}
@end