給WKWebView添加進度條（swift）

在WKWebView上添加進度條比在UIWebView上簡單了許多，並且是真的進度了，不用再自己去算比例或者造假的進度條了，

廢話少說，進入正題吧：

首先WKWebView有個屬性 UIProgressView

    /** 進度條 */
    var progressView : UIProgressView? = nil
    let keyPathForProgress : String = "estimatedProgress"

override func viewDidLoad() {
        super.viewDidLoad()

        initWebView()
        initProgressView()
    }

override func viewWillLayoutSubviews() {
        let width = self.view.bounds.size.width;
        let height = self.view.bounds.size.height;
        let statusBarBounds = UIApplication.sharedApplication().statusBarFrame
        
        let webViewHeight = height - 64 - 49
        webView.frame = CGRectMake(0, 64, width, webViewHeight)
        
    }

WKWebView代理

private func initWebView() {
        webView.navigationDelegate = self
        webView.UIDelegate = self
    }

WKWebView有一個屬性estimatedProgress，就是當前網頁加載的進度，所以首先監聽這個屬性。

private func initProgressView() {

        progressView = UIProgressView.init(frame: CGRectMake(0, 0, UILayoutDefine.KScreenWidth, 4))
　　　　　　// 這里可以改進度條顏色
        progressView!.tintColor = UIColor.greenColor()
        webView.addSubview(progressView!)
　　　　　　// 監聽
　　　　　　webView.addObserver(self, forKeyPath: keyPathForProgress, options: [NSKeyValueObservingOptions.New, NSKeyValueObservingOptions.Old], context: nil) 7 8 }

實現代理方法

/** 計算進度條 */
    override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) {
        if ((object?.isEqual(webView) != nil) && (keyPath! == keyPathForProgress) != nil) {
            let newProgress = change![NSKeyValueChangeNewKey]?.floatValue
            let oldProgress = change![NSKeyValueChangeOldKey]?.floatValue
            
            if newProgress < oldProgress {
                return
            }
            
            if newProgress >= 1 {
                progressView!.hidden = true
                progressView!.setProgress(0, animated: false)
            } else {
                progressView!.hidden = false
                progressView!.setProgress(newProgress!, animated: true)
            }
        } else {
            super.observeValueForKeyPath(keyPath, ofObject: object, change: change, context: context)
        }
    }

 

/**
     移除消息通知
     */
    deinit {
        webView .removeObserver(self, forKeyPath: keyPathForProgress)
        webView.navigationDelegate = nil
        webView.UIDelegate = nil
    }

OK 完成

參考：http://nshipster.cn/wkwebkit/