如何在更改 uiview 的隐藏模式时添加动画？

Question

我想在更改其隐藏模式时向视图添加动画，即

my_view.hidden=YES;

我在导航栏中添加了一个按钮。当我们单击它时，新视图将设置为取消隐藏。它绘制在导航表的上部。

Answer 1

将视图的不透明度从 100% 设置为 0%。让动画完成回调将视图设置为隐藏。您可能还想在回调期间将不透明度重置回 100%，这样当您取消隐藏视图时，视图将显示为完全不透明。

yourView.alpha = 0.0 //for zero opacity
yourView.alpha = 1.0 //for 100% opacity

Answer 2

然而，没有用于隐藏的动画；使用下面的 Swift 代码会得到相同的结果：

UIView.animate(withDuration: 0.2, delay: 0, options: [], animations: {            
    self.yourView.alpha = 0 // Here you can change the alpha property of the view 
}, completion: { _ in  
    self.yourView.isHidden = true // Here you hide it when animation done
})

Answer 3

不幸的是，hidden 不是一个可以通过 UIView 动画设置动画的属性。我认为你最好的选择可能是使用 @Erik B 建议的动画之一，或者开始涉足更强大的核心动画。浏览一下 UIView 动画和 Core Animations 的文档。

我通过使用 UIView 动画将新视图从另一个视图下方滑动来实现了类似于您建议的效果。这使它看起来像一个滑出的抽屉。如果你想做这样的事情，你需要拦截 touch up inside 事件并将动画代码放在那里。

- (IBAction)buttonClicked:(id)sender {
    [UIView animateWithDuration:0.5
                          delay:0.0 
                        options:UIViewAnimationCurveEaseOut
                     animations:^(void) {
                        self.myView.frame = /* set the frame here */
                     } 
                     completion:NULL];
}

Answer 4

我认为更合适的做法是：

[UIView transitionWithView:aView
                  duration:0.3
                   options:UIViewAnimationOptionTransitionCrossDissolve 
                animations:^(void){
                              aView.hidden = NO;
                           }
                completion:nil];

Answer 5

更新至 Swift 3：

UIView.animate(withDuration: 0.2, delay: 0.2, options: .curveEaseOut,
      animations: {firstView.alpha = 0}, 
      completion: { _ in firstView.isHidden = true
        //Do anything else that depends on this animation ending
    })

如果您希望在第一个视图消失后以动画方式恢复某些内容，您可以使用 alpha = 1 和 复制完成块内的代码隐藏=假。

Answer 6

这是我编写的一个类别，用于在 UIView 上引入一个新的“隐藏”属性，该属性正确支持动画：

@implementation UIView (AnimateHidden)

-(void)setHiddenAnimated:(BOOL)hide
{
  [UIView animateWithDuration:0.5
                        delay:0.0
                      options: UIViewAnimationCurveEaseOut
                   animations:^
                             {
                           [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
                           if (hide)
                             self.alpha=0;
                           else
                           {
                             self.hidden= NO;
                             self.alpha=1;
                           }
                         }
      completion:^(BOOL b)
      {
        if (hide)
          self.hidden= YES;
      }
  ];
}
@end

Answer 7

这是修正后的新泽西州版本：

@implementation UIView (AnimateHidden)

-(void)setHiddenAnimated:(BOOL)hide duration:(NSTimeInterval)duration {
    if(self.hidden == hide)
        return;
    if(hide)
        self.alpha = 1;
    else {
        self.alpha = 0;
        self.hidden = NO;
    }
    [UIView animateWithDuration:duration animations:^{
        if (hide)
            self.alpha = 0;
        else
            self.alpha = 1;
    } completion:^(BOOL finished) {
        if(finished)
            self.hidden = hide;
    }];
}

@end

Answer 8

这是 Swift 版本：

Swift 2

UIView.animateWithDuration(0.5, delay: 0.2, options: UIViewAnimationOptions.CurveEaseOut, animations: {
    objView.alpha = 0
}, completion: { finished in
    objView.hidden = true
})

Swift 3, 4, 5

UIView.animate(withDuration: 0.5, delay: 0.2, options: UIView.AnimationOptions.curveEaseOut, animations: {
    objView.alpha = 0
}, completion: { finished in
    objView.isHidden = true
})

它执行持续时间为 5 秒并延迟 2 秒后的动画。

可用的动画选项有：

CurveEaseInOut, CurveEaseIn, CurveEaseOut, CurveLinear

Answer 9

由于其中一些答案有点混乱，我想我可以发布我对此 API 的简约设计。我还添加了延迟和持续时间 - 因为为什么不呢。

在我们的实现中。

#import "UIView+AnimateHidden.h"

@implementation UIView (AnimateHidden)

- (void)setHiddenAnimated:(BOOL)hide
                    delay:(NSTimeInterval)delay
                 duration:(NSTimeInterval)duration {
    [UIView animateWithDuration:duration
                          delay:delay
                        options:UIViewAnimationOptionAllowAnimatedContent
                     animations:^{
                         if (hide) {
                             self.alpha = 0;
                         } else {
                             self.alpha = 0;
                             self.hidden = NO; // We need this to see the animation 0 -> 1
                             self.alpha = 1;
                         }
    } completion:^(BOOL finished) {
        self.hidden = hide;
    }];
}

@end

在我们的头文件中。

#import <UIKit/UIKit.h>

@interface UIView (AnimateHidden)

- (void)setHiddenAnimated:(BOOL)hide
                    delay:(NSTimeInterval)delay
                 duration:(NSTimeInterval)duration;

@end

Answer 10

NJ 和斯坦尼斯拉夫在这里的答案帮助我为此创建了一个新类别，我认为这改进了他们的答案，所以我想我会发布我的想法，以防它对其他人有帮助。

请注意，它仅适用于 iOS4 或更高版本，因为它使用块。

UIView+AnimateHidden.m

#import "UIView+AnimateHidden.h"

@implementation UIView (AnimateHidden)

- (void)setHidden:(BOOL)hidden animated:(BOOL)animated
{
    // If the hidden value is already set, do nothing
    if (hidden == self.hidden) {
        return;
    }
    // If no animation requested, do the normal setHidden method
    else if (animated == NO) {
        [self setHidden:hidden];
        return;
    }
    else {
        // Store the view's current alpha value
        CGFloat origAlpha = self.alpha;

        // If we're unhiding the view, make it invisible initially
        if (hidden == NO) {
            self.alpha = 0;
        }

        // Unhide the view so we can see the animation
        self.hidden = NO;

        // Do the animation
        [UIView animateWithDuration:0.5
                              delay:0.0
                            options: UIViewAnimationOptionCurveEaseOut
                         animations:^{
            // Start animation block
            if (hidden == YES) {
                self.alpha = 0;
            }
            else {
                self.alpha = origAlpha;
            }
            // End animation block
        }
                        completion:^(BOOL b){
            // Start completion block
            // Finish up by hiding the view if necessary...
            self.hidden = hidden;
            // ... and putting back the correct alpha value
            self.alpha = origAlpha;
            // End completion block
        }];
    }
}

@end

Answer 11

如果您希望使用更复杂的动画类型或 UIView 不支持的动画，请使用另一个版本

- (void)setHidden:(BOOL)hidden withAnimationDuration:(NSTimeInterval)duration
{
    CATransition* transition = ({
        CATransition* its = [CATransition animation];
        its.duration = duration;
        its.timingFunction =
            [CAMediaTimingFunction
             functionWithName: kCAMediaTimingFunctionEaseInEaseOut];
        its.type = kCATransitionPush;
        its.subtype = (hidden ? @"fromBottom" : @"fromTop");
        its
    });

    UIView* containerView = self.superview;
    [containerView.layer removeAllAnimations];
    [containerView.layer addAnimation: transition forKey: kCATransition];

    self.hidden = hidden;

    if (!hidden) {
        [self.superview bringSubviewToFront: self];
    }
}

Answer 12

这是我用来在“显示更多...”和“显示更少...”按钮单击时对视图“增长”和“收缩”进行建模的代码。根据 Palyancodr 的答案建模

这种方法允许我在故事板中创建两个视图，以便约束在不同的 iOS 设备上按预期工作，并且我不需要自定义所有约束的代码。

@IBAction func showMoreOrLessAction(_ sender: Any) {
    // if small view showing
    if showMoreLargeView.isHidden {
        showMoreSmallView.isHidden = true

        //showMoreLargeView.isHidden = false
        UIView.animate(withDuration: 0.2, delay: 0, options: [], animations: {
            self.showMoreLargeView.alpha = 1 // Here you will get the animation you want
        }, completion: { _ in
            self.showMoreLargeView.isHidden = false // Here you hide it when animation done
        })
    }
    else { // large view showing
        //showMoreSmallView.isHidden = false
        UIView.animate(withDuration: 0.2, delay: 0, options: [], animations: {
            self.showMoreSmallView.alpha = 1 // Here you will get the animation you want
        }, completion: { _ in
            self.showMoreSmallView.isHidden = false // Here you hide it when animation done
        })

        showMoreLargeView.isHidden = true
    }
}