【移動(dòng)應(yīng)用開(kāi)發(fā)技術(shù)】怎么在iOS中實(shí)現(xiàn)一個(gè)透明導(dǎo)航欄

【移動(dòng)應(yīng)用開(kāi)發(fā)技術(shù)】怎么在iOS中實(shí)現(xiàn)一個(gè)透明導(dǎo)航欄

這篇文章給大家介紹怎么在iOS中實(shí)現(xiàn)一個(gè)透明導(dǎo)航欄，內(nèi)容非常詳細(xì)，感興趣的小伙伴們可以參考借鑒，希望對(duì)大家能有所幫助。首先在需要設(shè)置導(dǎo)航欄透明的頁(yè)面的viewDidload中寫(xiě)上self.title

=

@"Title";

[self.navigationController.navigationBar

setBackgroundImage:[UIImage

new]

forBarMetrics:UIBarMetricsDefault];

self.navigationController.navigationBar.shadowImage

=

[UIImage

new];

self.barImageView

=

self.navigationController.navigationBar.subviews.firstObject;

self.barImageView.alpha

=

0;

//設(shè)置狀態(tài)欄

[[UIApplication

sharedApplication]

setStatusBarStyle:UIStatusBarStyleLightContent];

//設(shè)置標(biāo)題顏色

self.navigationController.navigationBar.titleTextAttributes

=

@{NSForegroundColorAttributeName

:

[UIColor

clearColor]};在scrollViewDidScroll代理方法中-(void)scrollViewDidScroll:(UIScrollView

*)scrollView

{

CGFloat

offset

=

scrollView.contentOffset.y;

//根據(jù)自己需要設(shè)置(136)的大小

CGFloat

alpha

=

offset

/

136;

_barImageView.alpha

=

alpha;

//記錄下當(dāng)前的透明度,在返回當(dāng)前頁(yè)面時(shí)需要

_alpha

=

alpha;

[[NSUserDefaults

standardUserDefaults]

setObject:[NSNumber

numberWithFloat:alpha]

forKey:@"_alpha"];

//設(shè)置標(biāo)題的透明度

self.navigationController.navigationBar.titleTextAttributes

=

@{NSForegroundColorAttributeName

:

[UIColor

colorWithWhite:0

alpha:alpha]};

}當(dāng)前頁(yè)的viewWillAppear,viewDidAppear,viewWillDisappear-(void)viewWillAppear:(BOOL)animated

{

[super

viewWillAppear:animated];

self.table.delegate

=

self;

}

-(void)viewDidAppear:(BOOL)animated

{

BOOL

isGesturePop

=

[[[NSUserDefaults

standardUserDefaults]

objectForKey:@"isGesturePop"]

boolValue];

if

(!isGesturePop)

{

_barImageView.alpha

=

_alpha;

self.navigationController.navigationBar.titleTextAttributes

=

@{NSForegroundColorAttributeName

:

[UIColor

colorWithWhite:0

alpha:_alpha]};

}

[super

viewDidAppear:animated];

}

-(void)viewWillDisappear:(BOOL)animated

{

[super

viewWillDisappear:animated];

self.table.delegate

=

nil;

self.navigationController.navigationBar.titleTextAttributes

=

@{NSForegroundColorAttributeName

:

[UIColor

blackColor]};

_barImageView.alpha

=

1;

[[NSUserDefaults

standardUserDefaults]

setObject:[NSNumber

numberWithBool:NO]

forKey:@"isGesturePop"];

}那么在我們需要push的下一個(gè)頁(yè)面需要什么操作呢,我們需要在這個(gè)頁(yè)面顯示正常的nav并且禁掉系統(tǒng)的手勢(shì)pop,自己寫(xiě)一個(gè)pop手勢(shì),以方便我們拿到pop滑動(dòng)時(shí)的偏移量,在做的時(shí)候使用了兩個(gè)類,在最后會(huì)有源碼貼出B.m須遵守UIGestureRecognizerDelegate,并導(dǎo)入NavigationInteractiveTransition.h全局變量@property

(nonatomic,

strong)

NavigationInteractiveTransition

*navT;viewDidLoadself.navigationCeractivePopGestureRecognizer.enabled

=

NO;

UIGestureRecognizer

*gesture

=

self.navigationCeractivePopGestureRecognizer;

gesture.enabled

=

NO;

UIView

*gestureView

=

gesture.view;

UIPanGestureRecognizer

*popRecognizer

=

[[UIPanGestureRecognizer

alloc]

init];

popRecognizer.delegate

=

self;

popRecognizer.maximumNumberOfTouches

=

1;

[gestureView

addGestureRecognizer:popRecognizer];

_navT

=

[[NavigationInteractiveTransition

alloc]

initWithViewController:self.navigationController];

[popRecognizer

addTarget:_navT

action:@selector(handleControllerPop:)];UIGestureRecognizerDelegate代理方法gestureRecognizerShouldBegin-

(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer

*)gestureRecognizer

{

//記錄當(dāng)前是是否是通過(guò)手勢(shì)滑動(dòng)回去

[[NSUserDefaults

standardUserDefaults]

setObject:[NSNumber

numberWithBool:YES]

forKey:@"isGesturePop"];

/**

*

這里有兩個(gè)條件不允許手勢(shì)執(zhí)行，1、當(dāng)前控制器為根控制器；2、如果這個(gè)push、pop動(dòng)畫(huà)正在執(zhí)行（私有屬性）

*/

return

self.navigationController.viewControllers.count

!=

1

&&

![[self.navigationController

valueForKey:@"_isTransitioning"]

boolValue];

}需要依賴的兩個(gè)類源碼NavigationInteractiveTransition.h#import

<UIKit/UIKit.h>

@class

UIViewController,

UIPercentDrivenInteractiveTransition;

@interface

NavigationInteractiveTransition

:

NSObject

<UINavigationControllerDelegate>

-

(instancetype)initWithViewController:(UIViewController

*)vc;

-

(void)handleControllerPop:(UIPanGestureRecognizer

*)recognizer;

-

(UIPercentDrivenInteractiveTransition

*)interactivePopTransition;

@endNavigationInteractiveTransition.m#import

"NavigationInteractiveTransition.h"

#import

"PopAnimation.h"

@interface

NavigationInteractiveTransition

()

@property

(nonatomic,

weak)

UINavigationController

*vc;

@property

(nonatomic,

strong)

UIPercentDrivenInteractiveTransition

*interactivePopTransition;

@property(nonatomic,

strong)

UIImageView

*barImageView;

@end

@implementation

NavigationInteractiveTransition

-

(instancetype)initWithViewController:(UIViewController

*)vc

{

self

=

[super

init];

if

(self)

{

self.vc

=

(UINavigationController

*)vc;

self.vc.delegate

=

self;

}

return

self;

}

/**

*

我們把用戶的每次Pan手勢(shì)操作作為一次pop動(dòng)畫(huà)的執(zhí)行

*/

-

(void)handleControllerPop:(UIPanGestureRecognizer

*)recognizer

{

/**

*

interactivePopTransition就是我們說(shuō)的方法2返回的對(duì)象，我們需要更新它的進(jìn)度來(lái)控制Pop動(dòng)畫(huà)的流程，我們用手指在視圖中的位置與視圖寬度比例作為它的進(jìn)度。

*/

CGFloat

progress

=

[recognizer

translationInView:recognizer.view].x

/

recognizer.view.bounds.size.width;

[self.vc.navigationBar

setBackgroundImage:[UIImage

new]

forBarMetrics:UIBarMetricsDefault];

self.vc.navigationBar.shadowImage

=

[UIImage

new];

self.barImageView

=

self.vc.navigationBar.subviews.firstObject;

CGFloat

alpha

=

[[[NSUserDefaults

standardUserDefaults]

objectForKey:@"_alpha"]

floatValue];

self.barImageView.alpha

=

1

-

progress

>

alpha

?

alpha

:

1

-

progress;

//

NSLog(@"===progress==%.2f",progress);

/**

*

穩(wěn)定進(jìn)度區(qū)間，讓它在0.0（未完成）～1.0（已完成）之間

*/

progress

=

MIN(1.0,

MAX(0.0,

progress));

if

(recognizer.state

==

UIGestureRecognizerStateBegan)

{

/**

*

手勢(shì)開(kāi)始，新建一個(gè)監(jiān)控對(duì)象

*/

eractivePopTransition

=

[[UIPercentDrivenInteractiveTransition

alloc]

init];

/**

*

告訴控制器開(kāi)始執(zhí)行pop的動(dòng)畫(huà)

*/

[self.vc

popViewControllerAnimated:YES];

}

else

if

(recognizer.state

==

UIGestureRecognizerStateChanged)

{

/**

*

更新手勢(shì)的完成進(jìn)度

*/

[eractivePopTransition

updateInteractiveTransition:progress];

}

else

if

(recognizer.state

==

UIGestureRecognizerStateEnded

||

recognizer.state

==

UIGestureRecognizerStateCancelled)

{

/**

*

手勢(shì)結(jié)束時(shí)如果進(jìn)度大于一半，那么就完成pop操作，否則重新來(lái)過(guò)。

*/

if

(progress

>

0.5)

{

[eractivePopTransition

finishInteractiveTransition];

self.barImageView.alpha

=

0;;

}

else

{

[eractivePopTransition

cancelInteractiveTransition];

}

eractivePopTransition

=

nil;

}

}

-

(id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController

*)navigationController

animationControllerForOperation:(UINavigationControllerOperation)operation

fromViewController:(UIViewController

*)fromVC

toViewController:(UIViewController

*)toVC

{

/**

*

方法1中判斷如果當(dāng)前執(zhí)行的是Pop操作，就返回我們自定義的Pop動(dòng)畫(huà)對(duì)象。

*/

if

(operation

==

UINavigationControllerOperationPop)

return

[[PopAnimation

alloc]

init];

return

nil;

}

-

(id<UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController

*)navigationController

interactionControllerForAnimationController:(id<UIViewControllerAnimatedTransitioning>)animationController

{

/**

*

方法2會(huì)傳給你當(dāng)前的動(dòng)畫(huà)對(duì)象animationController，判斷如果是我們自定義的Pop動(dòng)畫(huà)對(duì)象，那么就返回interactivePopTransition來(lái)監(jiān)控動(dòng)畫(huà)完成度。

*/

if

([animationController

isKindOfClass:[PopAnimation

class]])

return

eractivePopTransition;

return

nil;

}

@endPopAnimation.h#import

<Foundation/Foundation.h>

#import

<UIKit/UIKit.h>

@interface

PopAnimation

:

NSObject

<UIViewControllerAnimatedTransitioning>

@endPopAnimation.m#import

"PopAnimation.h"

@interface

PopAnimation

()

@property

(nonatomic,

strong)

id

<UIViewControllerContextTransitioning>

transitionContext;

@end

@implementation

PopAnimation

-

(NSTimeInterval)transitionDuration:(id

<UIViewControllerContextTransitioning>)transitionContext

{

//這個(gè)方法返回動(dòng)畫(huà)執(zhí)行的時(shí)間

return

0.25;

}

/**

*

transitionContext你可以看作是一個(gè)工具，用來(lái)獲取一系列動(dòng)畫(huà)執(zhí)行相關(guān)的對(duì)象，并且通知系統(tǒng)動(dòng)畫(huà)是否完成等功能。

*/

-

(void)animateTransition:(id

<UIViewControllerContextTransitioning>)transitionContext

{

/**

*

獲取動(dòng)畫(huà)來(lái)自的那個(gè)控制器

*/

UIViewController

*fromViewController

=

[transitionContext

viewControllerForKey:UITransitionContextFromViewControllerKey];

/**

*

獲取轉(zhuǎn)場(chǎng)到的那個(gè)控制器

*/

UIViewController

*toViewController

=

[transitionContext

viewControllerForKey:UITransitionContextToViewControllerKey];

/**

*

轉(zhuǎn)場(chǎng)動(dòng)畫(huà)是兩個(gè)控制器視圖時(shí)間的動(dòng)畫(huà)，需要一個(gè)contain