FREE: Watch my new YouTube videos, Xcode in 20 Seconds! >>

How to animate a blur effect using UIVisualEffectView

Paul Hudson       @twostraws

UIKit’s UIVisualEffectView class lets us add blurring effects to any view, optionally also combining a vibrancy effect to overlaid controls to help make them stand out. This makes it perfect for partly obscuring background content when you want to present information on top, and you can even animate that presentation if you want.

First, place a UIVisualEffectView into your view controller, either using code or using IB with an outlet.

When your app launches you should clear the effect property of your visual effect view, causing it to do nothing:

visualEffectView.effect = nil

When you want the blur to animate in – i.e., when you’re ready to show information on top – just set that effect property to a new instance of UIBlurEffect inside an animation block, like this:

UIView.animate(withDuration: 5) {
    self.visualEffectView.effect = UIBlurEffect(style: UIBlurEffect.Style.prominent)
}

UIKit will take care of the rest!

Sponsored You’re already busy updating your app for Swift 4.2 and iOS 12, so why not let Instabug help you find and fix bugs? Add just two lines of code to your project and receive comprehensive reports with all the feedback you need to ship a world-class app – click here to learn more!

Available from iOS 7.0

Did this solution work for you? Please pass it on!

Other people are reading…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

Upgrade your apps!

Take on Core ML, ARKit, PDFKit, Core NFC, and more all in one book that's packed with practical projects!

MASTER SWIFT NOW
Buy Testing Swift Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Click here to visit the Hacking with Swift store >>