在新iOS的音乐应用程序中,我们可以看到一个模糊的视图后面有一个专辑封面。
这样的事情是如何完成的呢?我看了文件,但什么都没发现。
在新iOS的音乐应用程序中,我们可以看到一个模糊的视图后面有一个专辑封面。
这样的事情是如何完成的呢?我看了文件,但什么都没发现。
当前回答
以下是Swift 2.0解决方案的代码,已经在接受的答案中提供:
//only apply the blur if the user hasn't disabled transparency effects
if !UIAccessibilityIsReduceTransparencyEnabled() {
self.view.backgroundColor = UIColor.clearColor()
let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
//always fill the view
blurEffectView.frame = self.view.bounds
blurEffectView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
self.view.addSubview(blurEffectView) //if you have more UIViews, use an insertSubview API to place it where needed
} else {
self.view.backgroundColor = UIColor.blackColor()
}
其他回答
2019代码
下面是一个使用@AdamBardon技巧的更完整的例子。
@IBDesignable class ButtonOrSomethingWithBlur: UIButton {
var ba: UIViewPropertyAnimator?
private lazy var blurry: BlurryBall = { return BlurryBall() }()
override func didMoveToSuperview() {
super.didMoveToSuperview()
// Setup the blurry ball. BE SURE TO TEARDOWN.
// Use superb trick to access the internal guassian level of Apple's
// standard gpu blurrer per stackoverflow.com/a/55378168/294884
superview?.insertSubview(blurry, belowSubview: self)
ba = UIViewPropertyAnimator(duration:1, curve:.linear) {[weak self] in
// note, those duration/curve values are simply unusued
self?.blurry.effect = UIBlurEffect(style: .extraLight)
}
ba?.fractionComplete = live.largeplaybutton_blurfactor
}
override func willMove(toSuperview newSuperview: UIView?) {
// Teardown for the blurry ball - critical
if newSuperview == nil { print("safe teardown")
ba?.stopAnimation(true)
ba?.finishAnimation(at: .current)
}
}
override func layoutSubviews() { super.layoutSubviews()
blurry.frame = bounds, your drawing frame or whatever
}
{题外话:作为一个通用的iOS工程问题,didMoveToWindow可能比didMoveToSuperview更适合你。其次,您可以使用其他一些方法来执行拆卸操作,但是拆卸操作就是这里显示的两行代码。
bluryball只是一个UIVisualEffectView。注意视觉效果视图的初始值。如果你碰巧需要圆角或者其他东西,在这门课上做吧。
class BlurryBall: UIVisualEffectView {
override init(effect: UIVisualEffect?) { super.init(effect: effect)
commonInit() }
required init?(coder aDecoder: NSCoder) { super.init(coder: aDecoder)
commonInit() }
private func commonInit() {
clipsToBounds = true
backgroundColor = .clear
}
override func layoutSubviews() {
super.layoutSubviews()
layer.cornerRadius = bounds.width / 2
}
}
我认为最简单的解决方案是覆盖UIToolbar,它在iOS 7中模糊了它后面的所有东西。这很狡猾,但实现起来非常简单,而且速度很快!
你可以对任何视图这么做,只是让它成为UIToolbar的子类而不是UIView。你甚至可以用UIViewController的view属性来做,例如…
1)创建一个新类,它是UIViewController的“子类”,并选中“With XIB for user interface”。
2)选择View,进入右边面板中的标识检查器(alt-command-3)。将“Class”改为UIToolbar。现在转到属性检查器(alt-command-4),将“背景”颜色改为“清色”。
3)在主视图中添加子视图,并将其连接到接口中的IBOutlet。叫它backgroundColorView。它看起来像这样,是实现(.m)文件中的一个私有类别。
@interface BlurExampleViewController ()
@property (weak, nonatomic) IBOutlet UIView *backgroundColorView;
@end
4)转到视图控制器实现(.m)文件并更改-viewDidLoad方法,如下所示:
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.barStyle = UIBarStyleBlack; // this will give a black blur as in the original post
self.backgroundColorView.opaque = NO;
self.backgroundColorView.alpha = 0.5;
self.backgroundColorView.backgroundColor = [UIColor colorWithWhite:0.3 alpha:1];
}
这将给你一个深灰色的视图,它模糊了它后面的一切。没有有趣的业务,没有缓慢的核心图像模糊,使用操作系统/SDK提供的一切。
你可以将这个视图控制器的视图添加到另一个视图,如下所示:
[self addChildViewController:self.blurViewController];
[self.view addSubview:self.blurViewController.view];
[self.blurViewController didMoveToParentViewController:self];
// animate the self.blurViewController into view
如果有什么不清楚的地方请告诉我,我很乐意帮忙!
Edit
UIToolbar在7.0.3中被改变,当使用彩色模糊时可能会产生不希望看到的效果。
我们过去能够使用barTintColor设置颜色,但如果你以前这样做,你将需要将alpha组件设置为小于1。否则你的UIToolbar将是完全不透明的颜色-没有模糊。
这可以通过如下方式实现:(记住self是UIToolbar的子类)
UIColor *color = [UIColor blueColor]; // for example
self.barTintColor = [color colorWithAlphaComponent:0.5];
这将给模糊的视图一个蓝色的色调。
func blurBackgroundUsingImage(image: UIImage)
{
var frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height)
var imageView = UIImageView(frame: frame)
imageView.image = image
imageView.contentMode = .ScaleAspectFill
var blurEffect = UIBlurEffect(style: .Light)
var blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = frame
var transparentWhiteView = UIView(frame: frame)
transparentWhiteView.backgroundColor = UIColor(white: 1.0, alpha: 0.30)
var viewsArray = [imageView, blurEffectView, transparentWhiteView]
for index in 0..<viewsArray.count {
if let oldView = self.view.viewWithTag(index + 1) {
var oldView = self.view.viewWithTag(index + 1)
// Must explicitly unwrap oldView to access its removeFromSuperview() method as of Xcode 6 Beta 5
oldView!.removeFromSuperview()
}
var viewToInsert = viewsArray[index]
self.view.insertSubview(viewToInsert, atIndex: index + 1)
viewToInsert.tag = index + 1
}
}
下面是一个简单的方法来添加自定义模糊,而不用与私有api讨价还价使用UIViewPropertyAnimator:
首先,声明class属性:
var blurAnimator: UIViewPropertyAnimator!
然后在viewDidLoad()中设置你的模糊视图:
let blurEffectView = UIVisualEffectView()
blurEffectView.backgroundColor = .clear
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView)
blurAnimator = UIViewPropertyAnimator(duration: 1, curve: .linear) { [blurEffectView] in
blurEffectView.effect = UIBlurEffect(style: .light)
}
blurAnimator.fractionComplete = 0.15 // set the blur intensity.
注意:此解决方案不适用于UICollectionView/UITableView单元格
这是乔伊回答的重要补充
这适用于你想用UINavigationController呈现一个模糊背景的UIViewController的情况。
// suppose you've done blur effect with your presented view controller
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController];
// this is very important, if you don't do this, the blur effect will darken after view did appeared
// the reason is that you actually present navigation controller, not presented controller
// please note it's "OverFullScreen", not "OverCurrentContext"
nav.modalPresentationStyle = UIModalPresentationOverFullScreen;
UIViewController *presentedViewController = [[UIViewController alloc] init];
// the presented view controller's modalPresentationStyle is "OverCurrentContext"
presentedViewController.modalPresentationStyle = UIModalPresentationOverCurrentContext;
[presentingViewController presentViewController:nav animated:YES completion:nil];
享受吧!