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
你可以使用UIVisualEffectView来实现这个效果。这是一个本地API,经过了性能和电池寿命的微调,而且很容易实现。
迅速:
//only apply the blur if the user hasn't disabled transparency effects
if !UIAccessibility.isReduceTransparencyEnabled {
view.backgroundColor = .clear
let blurEffect = UIBlurEffect(style: .dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
//always fill the view
blurEffectView.frame = self.view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView) //if you have more UIViews, use an insertSubview API to place it where needed
} else {
view.backgroundColor = .black
}
objective - c:
//only apply the blur if the user hasn't disabled transparency effects
if (!UIAccessibilityIsReduceTransparencyEnabled()) {
self.view.backgroundColor = [UIColor clearColor];
UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];
UIVisualEffectView *blurEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
//always fill the view
blurEffectView.frame = self.view.bounds;
blurEffectView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[self.view addSubview:blurEffectView]; //if you have more UIViews, use an insertSubview API to place it where needed
} else {
self.view.backgroundColor = [UIColor blackColor];
}
如果你以模态方式呈现这个视图控制器来模糊底层内容,你需要将模态呈现风格设置为Over Current Context,并将背景颜色设置为clear,以确保底层视图控制器在顶部呈现时仍然可见。
其他回答
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。
自定义模糊比例
你可以尝试UIVisualEffectView自定义设置为-
class BlurViewController: UIViewController {
private let blurEffect = (NSClassFromString("_UICustomBlurEffect") as! UIBlurEffect.Type).init()
override func viewDidLoad() {
super.viewDidLoad()
let blurView = UIVisualEffectView(frame: UIScreen.main.bounds)
blurEffect.setValue(1, forKeyPath: "blurRadius")
blurView.effect = blurEffect
view.addSubview(blurView)
}
}
输出:- for blureeffect . setvalue(1…& blurEffect.setValue (2 . .
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!
如果为tableView添加一个暗模糊视图,这将漂亮地使它:
tableView.backgroundColor = .clear
let blurEffect = UIBlurEffect(style: .dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = tableView.bounds
blurEffectView.autoresizingMask = [.flexibleHeight, .flexibleWidth]
// Assigning blurEffectView to backgroundView instead of addSubview to tableView makes tableView cell not blocked by blurEffectView
tableView.backgroundView = blurEffectView
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
}
}