Swift國內(nèi)社區(qū): SwiftMic

本篇文章介紹如何實(shí)現(xiàn) iOS 切換 app 預(yù)覽模糊的效果。

最終效果：

blur_demo_snapshot_blur.png

blur_demo_snapshot_normal.png

只需修改 AppDelegate.swift 即可。

首先聲明一個變量 mBlurView

private var mBlurView: UIView!

增加 getBlurView() 方法

private func getBlurView() -> UIView {
    if nil == mBlurView {
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Light)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = UIScreen.mainScreen().bounds
            
        mBlurView = blurEffectView
    }
        
    return mBlurView
}

當(dāng) app 處于 inactive 狀態(tài)時， 添加 blur view 。

func applicationWillResignActive(application: UIApplication) {
    // Add blur view
    UIApplication.sharedApplication().keyWindow?.addSubview(getBlurView())
}

當(dāng) app 處于 active 狀態(tài)時， 移除 blur view 。

func applicationDidBecomeActive(application: UIApplication) {
    // Remove blur view
    if nil != mBlurView {
        mBlurView.removeFromSuperview()
    }
}

完整代碼示例： iOSDemoCollection -> BlurDemo