iOS]自动添加NavigationController自定义按钮动画 并且管理堆栈

http://blog.cnbang.net/tech/1778/

 

问题

UINavigationController顶部的返回按钮在切换视图时有左右滑动的动画(效果见iMail)，但在自定义了这个按钮后(通过设self.navigationItem.leftBarButtonItem自定义)，切换视图时按钮没有了动画。

最初解决方法

在每个viewController的viewWillAppear和viewDisappear方法上手动让按钮左右动。由于每个视图出现/消失的方向都有左/右两种，在这里难以判断，需要各种变量辅助，实现十分恶心，中间需要新加view时逻辑还要重新修改，被折腾。

最终解决方法

继承UINavigationController，重写pushViewController和popViewController方法，在这两 个方法里面获取NavigationController里的view栈，因为push和pop总是操作最前面的View，所以可以从栈里知道哪两个 view是要做动画的。调用这些view相应的方法使他们让自己的按钮动。这些方法可以写在UIViewController的扩展里，不用修改每一个 viewController。

换言之，把下面的代码加入项目里，把项目里的UINavigationController换成下面的类，那些自定义的返回按钮就会自动做动画了。

代码

https://github.com/bang590/iOSPlayground/tree/master/NavigationButtonAnimate

查看源代码打印帮助

01.//.h

02.#import <Foundation/Foundation.h>

03.@interface MainNavigationController : UINavigationController {

04.}

05.@end

06. 

07.//.m

08.#import "MainNavigationController.h"

09.@implementation UIViewController (UINavigationButtonAnimate)

10.- (void) viewAppearFromLeft

11.{

12.    [self.navigationItem.leftBarButtonItem.customView setTransform:CGAffineTransformMakeTranslation(-60, 0)];

13.    [UIView beginAnimations:@"viewAppearFromLeft" context:nil];

14.    [UIView setAnimationDuration:0.3];

15.    [self.navigationItem.leftBarButtonItem.customView setAlpha:1.0];

16.    [self.navigationItem.leftBarButtonItem.customView setTransform:CGAffineTransformMakeTranslation(0, 0)];

17.    [UIView commitAnimations];

18.}

19.- (void) viewAppearFromRight

20.{

21.    [self.navigationItem.leftBarButtonItem.customView setTransform:CGAffineTransformMakeTranslation(60, 0)];

22.    [UIView beginAnimations:@"viewAppearFromRight" context:nil];

23.    [UIView setAnimationDuration:0.3];

24.    [self.navigationItem.leftBarButtonItem.customView setAlpha:1.0];

25.    [self.navigationItem.leftBarButtonItem.customView setTransform:CGAffineTransformMakeTranslation(0, 0)];

26.    [UIView commitAnimations];

27.}

28.- (void) viewDisappearFromLeft

29.{

30.    [UIView beginAnimations:@"viewDisappearFromLeft" context:nil];

31.    [self.navigationItem.leftBarButtonItem.customView setTransform:CGAffineTransformMakeTranslation(60, 0)];

32.    [UIView setAnimationDuration:0.3];

33.    [self.navigationItem.leftBarButtonItem.customView setAlpha:0];

34.    [UIView commitAnimations];

35.}

36.- (void) viewDisappearFromRight

37.{

38.    [UIView beginAnimations:@"viewDisappearFromRight" context:nil];

39.    [self.navigationItem.leftBarButtonItem.customView setTransform:CGAffineTransformMakeTranslation(-60, 0)];

40.    [UIView setAnimationDuration:0.3];

41.    [self.navigationItem.leftBarButtonItem.customView setAlpha:0];

42.    [UIView commitAnimations];

43.}

44.@end

45. 

46.@implementation MainNavigationController

47.- (UIViewController *)popViewControllerAnimated:(BOOL)animated

48.{

49.    if (animated) {

50.        UIViewController *popController = [self.viewControllers lastObject];

51.        UIViewController *pushController = [self.viewControllers objectAtIndex:self.viewControllers.count - 2];

52.        [popController viewDisappearFromLeft];

53.        [pushController viewAppearFromLeft];

54.    }

55.    return [super popViewControllerAnimated:animated];

56.}

57.- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated

58.{

59.    if (animated) {

60.        UIViewController *popController = [self.viewControllers lastObject];

61.        UIViewController *pushController = viewController;

62.        [popController viewDisappearFromRight];

63.        [pushController viewAppearFromRight];

64.    }

65.    [super pushViewController:viewController animated:animated];

66.}

67.@end