我的简单目标是淡化动画隐藏和显示功能。
Button.hidden = YES;
足够简单。但是，是否有可能让它淡出而不仅仅是消失？这样看起来很不专业。
答案 0 :(得分：241)
在iOS 4及更高版本中，有一种方法可以使用UIView转换方法执行此操作，而无需导入QuartzCore。你可以说：
[UIView transitionWithView:button
duration:0.4
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{
button.hidden = YES;
}
completion:NULL];
Michail的解决方案可行，但实际上并不是最好的方法。
alpha衰落的问题在于，有时不同的重叠视图层在淡出时看起来很奇怪。还有一些使用Core Animation的替代方案。首先在您的应用中包含QuartzCore框架，然后将#import <QuartzCore/QuartzCore.h>添加到标头中。现在您可以执行以下操作之一：
1）设置button.layer.shouldRasterize = YES;，然后使用Michail在答案中提供的alpha动画代码。这样可以防止图层奇怪地混合，但会有轻微的性能损失，并且如果按钮没有在像素边界上精确对齐，可能会使按钮看起来模糊。
可替换地：
2）使用以下代码为fade设置动画：
CATransition *animation = [CATransition animation];
animation.type = kCATransitionFade;
animation.duration = 0.4;
[button.layer addAnimation:animation forKey:nil];
button.hidden = YES;
这种方法的好处是你可以交叉淡化按钮的任何属性，即使它们不是可动画的（例如按钮的文本或图像），只需设置过渡，然后立即设置你的属性。 / p>
答案 1 :(得分：136)
UIView动画属性是：
- frame
- bounds
- center
- transform
- alpha
- backgroundColor
- contentStretch
描述于： Animations
isHidden不是其中之一，所以我认为最好的方法是：
Swift 4：
func setView(view: UIView, hidden: Bool) {
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.isHidden = hidden
})
}
目标C：
- (void)setView:(UIView*)view hidden:(BOOL)hidden {
[UIView transitionWithView:view duration:0.5 options:UIViewAnimationOptionTransitionCrossDissolve animations:^(void){
[view setHidden:hidden];
} completion:nil];
}
答案 2 :(得分：113)
淡出：
[UIView animateWithDuration:0.3 animations:^{
button.alpha = 0;
} completion: ^(BOOL finished) {//creates a variable (BOOL) called "finished" that is set to *YES* when animation IS completed.
button.hidden = finished;//if animation is finished ("finished" == *YES*), then hidden = "finished" ... (aka hidden = *YES*)
}];
// swift:
UIView.animateWithDuration(0.3, animations: {
button.alpha = 0
}) { (finished) in
button.hidden = finished
}
淡出：
button.alpha = 0;
button.hidden = NO;
[UIView animateWithDuration:0.3 animations:^{
button.alpha = 1;
}];
// swift:
button.alpha = 0
button.hidden = false
UIView.animateWithDuration(0.3) {
button.alpha = 1
}
答案 3 :(得分：8)
我使用这个 Swift 3 扩展名
extension UIView {
func fadeIn(duration: TimeInterval = 0.5,
delay: TimeInterval = 0.0,
completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in }) {
UIView.animate(withDuration: duration,
delay: delay,
options: UIViewAnimationOptions.curveEaseIn,
animations: {
self.alpha = 1.0
}, completion: completion)
}
func fadeOut(duration: TimeInterval = 0.5,
delay: TimeInterval = 0.0,
completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in }) {
UIView.animate(withDuration: duration,
delay: delay,
options: UIViewAnimationOptions.curveEaseIn,
animations: {
self.alpha = 0.0
}, completion: completion)
}
}
答案 4 :(得分：7)
Swift 3
func appearView() {
self.myView.alpha = 0
self.myView.isHidden = false
UIView.animate(withDuration: 0.9, animations: {
self.myView.alpha = 1
}, completion: {
finished in
self.myView.isHidden = false
})
}
答案 5 :(得分：6)
我为此目的为UIView创建了类别，并实现了一个特殊的不同概念：visibility。我的解决方案的主要区别在于您可以调用[view setVisible:NO animated:YES]并在此之后立即同步检查[view visible]并获得正确的结果。这非常简单但非常有用。
此外，允许避免使用“否定布尔逻辑”（有关更多信息，请参阅Code Complete, page 269, Use positive boolean variable names）。
UIView+Visibility.swift
import UIKit
private let UIViewVisibilityShowAnimationKey = "UIViewVisibilityShowAnimationKey"
private let UIViewVisibilityHideAnimationKey = "UIViewVisibilityHideAnimationKey"
private class UIViewAnimationDelegate: NSObject {
weak var view: UIView?
dynamic override func animationDidStop(animation: CAAnimation, finished: Bool) {
guard let view = self.view where finished else {
return
}
view.hidden = !view.visible
view.removeVisibilityAnimations()
}
}
extension UIView {
private func removeVisibilityAnimations() {
self.layer.removeAnimationForKey(UIViewVisibilityShowAnimationKey)
self.layer.removeAnimationForKey(UIViewVisibilityHideAnimationKey)
}
var visible: Bool {
get {
return !self.hidden && self.layer.animationForKey(UIViewVisibilityHideAnimationKey) == nil
}
set {
let visible = newValue
guard self.visible != visible else {
return
}
let animated = UIView.areAnimationsEnabled()
self.removeVisibilityAnimations()
guard animated else {
self.hidden = !visible
return
}
self.hidden = false
let delegate = UIViewAnimationDelegate()
delegate.view = self
let animation = CABasicAnimation(keyPath: "opacity")
animation.fromValue = visible ? 0.0 : 1.0
animation.toValue = visible ? 1.0 : 0.0
animation.fillMode = kCAFillModeForwards
animation.removedOnCompletion = false
animation.delegate = delegate
self.layer.addAnimation(animation, forKey: visible ? UIViewVisibilityShowAnimationKey : UIViewVisibilityHideAnimationKey)
}
}
func setVisible(visible: Bool, animated: Bool) {
let wereAnimationsEnabled = UIView.areAnimationsEnabled()
if wereAnimationsEnabled != animated {
UIView.setAnimationsEnabled(animated)
defer { UIView.setAnimationsEnabled(!animated) }
}
self.visible = visible
}
}
UIView+Visibility.h
#import <UIKit/UIKit.h>
@interface UIView (Visibility)
- (BOOL)visible;
- (void)setVisible:(BOOL)visible;
- (void)setVisible:(BOOL)visible animated:(BOOL)animated;
@end
UIView+Visibility.m
#import "UIView+Visibility.h"
NSString *const UIViewVisibilityAnimationKeyShow = @"UIViewVisibilityAnimationKeyShow";
NSString *const UIViewVisibilityAnimationKeyHide = @"UIViewVisibilityAnimationKeyHide";
@implementation UIView (Visibility)
- (BOOL)visible
{
if (self.hidden || [self.layer animationForKey:UIViewVisibilityAnimationKeyHide]) {
return NO;
}
return YES;
}
- (void)setVisible:(BOOL)visible
{
[self setVisible:visible animated:NO];
}
- (void)setVisible:(BOOL)visible animated:(BOOL)animated
{
if (self.visible == visible) {
return;
}
[self.layer removeAnimationForKey:UIViewVisibilityAnimationKeyShow];
[self.layer removeAnimationForKey:UIViewVisibilityAnimationKeyHide];
if (!animated) {
self.alpha = 1.f;
self.hidden = !visible;
return;
}
self.hidden = NO;
CGFloat fromAlpha = visible ? 0.f : 1.f;
CGFloat toAlpha = visible ? 1.f : 0.f;
NSString *animationKey = visible ? UIViewVisibilityAnimationKeyShow : UIViewVisibilityAnimationKeyHide;
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
animation.duration = 0.25;
animation.fromValue = @(fromAlpha);
animation.toValue = @(toAlpha);
animation.delegate = self;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
[self.layer addAnimation:animation forKey:animationKey];
}
#pragma mark - CAAnimationDelegate
- (void)animationDidStop:(CAAnimation *)animation finished:(BOOL)finished
{
if ([[self.layer animationForKey:UIViewVisibilityAnimationKeyHide] isEqual:animation]) {
self.hidden = YES;
}
}
@end
答案 6 :(得分：4)
快捷键4
extension UIView {
func fadeIn(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in }) {
self.alpha = 0.0
UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
self.isHidden = false
self.alpha = 1.0
}, completion: completion)
}
func fadeOut(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in }) {
self.alpha = 1.0
UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
self.alpha = 0.0
}) { (completed) in
self.isHidden = true
completion(true)
}
}
}
要使用它，只需调用以下函数即可：
yourView.fadeOut() // this will hide your view with animation
yourView.fadeIn() /// this will show your view with animation
答案 7 :(得分：2)
迅速4.2
扩展名：
extension UIView {
func hideWithAnimation(hidden: Bool) {
UIView.transition(with: self, duration: 0.5, options: .transitionCrossDissolve, animations: {
self.isHidden = hidden
})
}
}
简单方法：
func setView(view: UIView, hidden: Bool) {
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.isHidden = hidden
})
}
答案 8 :(得分：2)
Swift 5.0，具有泛型：
func hideViewWithAnimation<T: UIView>(shouldHidden: Bool, objView: T) {
if shouldHidden == true {
UIView.animate(withDuration: 0.3, animations: {
objView.alpha = 0
}) { (finished) in
objView.isHidden = shouldHidden
}
} else {
objView.alpha = 0
objView.isHidden = shouldHidden
UIView.animate(withDuration: 0.3) {
objView.alpha = 1
}
}
}
使用：
hideViewWithAnimation(shouldHidden: shouldHidden, objView: itemCountLabelBGView)
hideViewWithAnimation(shouldHidden: shouldHidden, objView: itemCountLabel)
hideViewWithAnimation(shouldHidden: shouldHidden, objView: itemCountButton)
这里itemCountLabelBGView是UIView，itemCountLabel是UILabel＆itemCountButton是UIButton，因此适用于每个视图父类为UIView的对象。
答案 9 :(得分：1)
func flipViews(fromView: UIView, toView: UIView) {
toView.frame.origin.y = 0
self.view.isUserInteractionEnabled = false
UIView.transition(from: fromView, to: toView, duration: 0.5, options: .transitionFlipFromLeft, completion: { finished in
fromView.frame.origin.y = -900
self.view.isUserInteractionEnabled = true
})
}
答案 10 :(得分：1)
你可以试试这个。
func showView(objView:UIView){
objView.alpha = 0.0
UIView.animate(withDuration: 0.5, animations: {
objView.alpha = 0.0
}, completion: { (completeFadein: Bool) -> Void in
objView.alpha = 1.0
let transition = CATransition()
transition.duration = 0.5
transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.type = kCATransitionFade
objView.layer.add(transition, forKey: nil)
})
}
func HideView(objView:UIView){
UIView.animate(withDuration: 0.5, animations: {
objView.alpha = 1.0
}, completion: { (completeFadein: Bool) -> Void in
objView.alpha = 0.0
let transition = CATransition()
transition.duration = 0.5
transition.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.type = kCATransitionFade
objView.layer.add(transition, forKey: nil)
})
}
并传递您的观点名称
showView(objView: self.viewSaveCard)
HideView(objView: self.viewSaveCard)
答案 11 :(得分：1)
您可以使用Animatics库非常轻松地执行此操作：
//To hide button:
AlphaAnimator(0) ~> button
//to show button
AlphaAnimator(1) ~> button
答案 12 :(得分：1)
如果默认情况下视图设置为“隐藏”或更改了“隐藏”状态（在许多情况下，我认为您应该这样做），则此页面中的任何一种方法都不会同时给您提供FadeIn / FadeOut动画，它只会为其中一个动画这些状态，原因是您在调用 UIView.animate 方法之前将Hidden状态设置为false，这将导致突然的可见性；如果仅对alpha进行动画处理，则对象空间仍然存在，但不是可见，这将导致某些UI问题。
所以最好的方法是先检查视图是否被隐藏，然后将alpha设置为0.0，这样，当您将Hidden状态设置为false时，您将不会看到可见的图像。
func hideViewWithFade(_ view: UIView) {
if view.isHidden {
view.alpha = 0.0
}
view.isHidden = false
UIView.animate(withDuration: 0.3, delay: 0.0, options: .transitionCrossDissolve, animations: {
view.alpha = view.alpha == 1.0 ? 0.0 : 1.0
}, completion: { _ in
view.isHidden = !Bool(truncating: view.alpha as NSNumber)
})
}
答案 13 :(得分：1)
UIView.transition（with :)函数非常简洁。
许多已发布，但没有人注意到只有在运行时才会显示错误。
您可以将隐藏属性完美地转换为true，而当您尝试将其转换为false时，视图将突然消失而没有任何动画。
那是因为此api仅在视图中内起作用，这意味着当您转换视图以显示（实际上本身会立即显示）时，仅其内容会逐渐显示出来。
当您尝试隐藏此视图时，其本身会立即隐藏，从而使动画内容无意义。
为解决此问题，在隐藏视图时，过渡目标应该是其父视图，而不是要隐藏的视图。
func transitionView(_ view: UIView?, show: Bool, completion: BoolFunc? = nil) {
guard let view = view, view.isHidden == show, let parent = view.superview else { return }
let target: UIView = show ? view : parent
UIView.transition(with: target, duration: 0.4, options: [.transitionCrossDissolve], animations: {
view.isHidden = !show
}, completion: completion)
}
答案 14 :(得分：0)
我对 Swift 3 的解决方案。所以，我创建了这个函数，以正确的顺序隐藏/取消隐藏视图（隐藏时 - 将alpha设置为0，然后将isHidden设置为true;取消隐藏 - 首先显示视图，然后将其alpha设置为1）：
func hide(_ hide: Bool) {
let animations = hide ? { self.alpha = 0 } :
{ self.isHidden = false }
let completion: (Bool) -> Void = hide ? { _ in self.isHidden = true } :
{ _ in UIView.animate(withDuration: duration, animations: { self.alpha = 1 }) }
UIView.animate(withDuration: duration, animations: animations, completion: completion)
}
答案 15 :(得分：0)
Swift 4 Transition
UIView.transition(with: view, duration: 3, options: .transitionCurlDown,
animations: {
// Animations
view.isHidden = hidden
},
completion: { finished in
// Compeleted
})
如果您使用旧版swift版本的方法，则会收到错误：
Cannot convert value of type '(_) -> ()' to expected argument type '(() -> Void)?'
有用的reference。
答案 16 :(得分：0)
此代码给出了一个动画，例如将viewController推入 uinavigation控制器...
CATransition *animation = [CATransition animation];
animation.type = kCATransitionPush;
animation.subtype = kCATransitionFromRight;
animation.duration = 0.3;
[_viewAccountName.layer addAnimation:animation forKey:nil];
_viewAccountName.hidden = true;
将其用于流行动画...
CATransition *animation = [CATransition animation];
animation.type = kCATransitionPush;
animation.subtype = kCATransitionFromLeft;
animation.duration = 0.3;
[_viewAccountName.layer addAnimation:animation forKey:nil];
_viewAccountName.hidden = false;
答案 17 :(得分：0)
尝试了一些已存在的答案，有些仅在一种情况下有效，其中一些需要添加两个功能。
选项1
与view.isHidden无关。
extension UIView {
func animate(fadeIn: Bool, withDuration: TimeInterval = 1.0) {
UIView.animate(withDuration: withDuration, delay: 0.0, options: .curveEaseInOut, animations: {
self.alpha = fadeIn ? 1.0 : 0.0
})
}
}
然后通过isFadeIn（true或false）
view.animate(fadeIn: isFadeIn)
选项2
不传递任何参数。它根据isUserInteractionEnabled淡入或淡出。这也非常适合来回动画的情况。
func animateFadeInOut(withDuration: TimeInterval = 1.0) {
self.isUserInteractionEnabled = !self.isUserInteractionEnabled
UIView.animate(withDuration: withDuration, delay: 0.0, options: .curveEaseInOut, animations: {
self.alpha = self.isUserInteractionEnabled ? 1.0 : 0.0
})
}
然后致电
yourView.animateFadeInOut()
为什么要
self.isUserInteractionEnabled？试图将
self.isUserInteractionEnabled替换为self.isHidden， 完全没有运气。
就是这样。花了我一些时间，希望它能对某人有所帮助。
答案 18 :(得分：0)
@Umair Afzal的代码在进行一些更改后可以在Swift 5中正常工作
extension UIView {
func fadeIn(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in }) {
self.alpha = 0.0
UIView.animate(withDuration: duration, delay: delay, options: UIView.AnimationOptions.curveEaseIn, animations: {
self.isHidden = false
self.alpha = 1.0
}, completion: completion)
}
func fadeOut(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in }) {
self.alpha = 1.0
UIView.animate(withDuration: duration, delay: delay, options: UIView.AnimationOptions.curveEaseIn, animations: {
self.alpha = 0.0
}) { (completed) in
self.isHidden = true
completion(true)
}
}
}
使用
yourView.fadeOut()
yourView.fadeIn()
答案 19 :(得分：0)
使用此解决方案可获得平滑的fadeOut和fadeIn效果
extension UIView {
func fadeIn(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in }) {
self.alpha = 0.0
UIView.animate(withDuration: duration, delay: delay, options: UIView.AnimationOptions.curveEaseIn, animations: {
self.isHidden = false
self.alpha = 1.0
}, completion: completion)
}
func fadeOut(duration: TimeInterval = 0.5, delay: TimeInterval = 0.0, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in }) {
self.alpha = 1.0
UIView.animate(withDuration: duration, delay: delay, options: UIView.AnimationOptions.curveEaseOut, animations: {
self.isHidden = true
self.alpha = 0.0
}, completion: completion)
}
}
用法就像
uielement.fadeIn()
uielement.fadeOut()
谢谢
答案 20 :(得分：0)
isHidden是一个立即值，您不能影响动画，相反，您可以使用Alpha来隐藏视图
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.alpha = 0
})
并显示：
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.alpha = 1
})
答案 21 :(得分：-1)
UIView.transition(with: title3Label, duration: 0.4,
options: .transitionCrossDissolve,
animations: {
self.title3Label.isHidden = !self.title3Label.isHidden
})
在View上稍加延迟即可实现隐藏和显示效果