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WKWebView使用简介

96
Cocfish
2016.08.30 10:48* 字数 238

Demo链接:https://github.com/3KK3/WKWebViewAndLoadNativeAddressbook

WKWebView是苹果iOS8后推出的用来替代UIWebView的新控件,iOS9后又推出缓存相关的API。

iOS端调用js端方法:#####
 //直接调用js 
  webView.evaluateJavaScript("hi()", completionHandler: nil)
 //调用js带参数 
  webView.evaluateJavaScript("hello('liuyanwei')", completionHandler: nil) 
  //调用js获取返回值 
  webView.evaluateJavaScript("getName()") { (any,error) -> Void in
   NSLog("%@", any as! String) 
}

注:WKWebView绝大多数睡醒支持kvo
比如想要在网页加载完成后执行某些操作,可以监控WKWebView的loading属性:

  self.webView.addObserver(self, forKeyPath: "loading", options: .New, context: nil)

然后在监控方法执行操作:

  override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) {
    if keyPath == "loading" {
      print("loading")
    } 
    // 已经完成加载时,我们就可以做我们的事了
    if !webView.loading {
     //TODO:
    }
  }
WKWebView还支持iOS端往js端注入代码#####
    // 创建一个webiview的配置项
    let configuretion = WKWebViewConfiguration()

    // 添加一个JS到HTML中,这样就可以直接在JS中调用我们添加的JS方法
    let script = WKUserScript(source: "function showAlert() { alert('在载入webview时通过Swift注入的JS方法'); }",
      injectionTime: .AtDocumentStart,// 在载入时就添加JS
      forMainFrameOnly: true) // 只添加到mainFrame中

    configuretion.userContentController.addUserScript(script)
js端调用iOS端方法#####

1).js端代码要求:
在js端点击事件处,想iOS端发送message信息,代码格式为:


<script type="text/javascript">

   function callJsAlert() {
    alert('Objective-C call js to show alert');    //注意①
    window.webkit.messageHandlers.消息名.postMessage({body: 'this body can be received by iOS platform'});
   }
</script>

注意①:WKWebView中,js端的弹框alert事件,需要在iOS端通过WKUIDelegate的三个代理runJavaScriptAlertPanelWithMessage runJavaScriptConfirmPanelWithMessage和runJavaScriptTextInputPanelWithPrompt来实现。比如上面js代码中的alert('Objective-C call js to show alert');事件 ,需要在iOS端:

override func viewDidLoad() {
  self.webView.UIDelegate = self
}

// MARK: - WKUIDelegate
func webView(webView: WKWebView, runJavaScriptAlertPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: () -> Void) {
  let alert = UIAlertController(title: "Tip", message: message, preferredStyle: .Alert)
  alert.addAction(UIAlertAction(title: "Ok", style: .Default, handler: { (_) -> Void in
    // We must call back js
    completionHandler()
  }))
  
  self.presentViewController(alert, animated: true, completion: nil)
}

func webView(webView: WKWebView, runJavaScriptConfirmPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: (Bool) -> Void) {
  let alert = UIAlertController(title: "Tip", message: message, preferredStyle: .Alert)
  alert.addAction(UIAlertAction(title: "Ok", style: .Default, handler: { (_) -> Void in
    completionHandler(true)
  }))
  alert.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: { (_) -> Void in
    completionHandler(false)
  }))
  
  self.presentViewController(alert, animated: true, completion: nil)
}

//带输入框的alertview
func webView(webView: WKWebView, runJavaScriptTextInputPanelWithPrompt prompt: String, defaultText: String?, initiatedByFrame frame: WKFrameInfo, completionHandler: (String?) -> Void) {
    
  let alert = UIAlertController(title: prompt, message: defaultText, preferredStyle: .Alert)
  
  alert.addTextFieldWithConfigurationHandler { (textField: UITextField) -> Void in
    textField.textColor = UIColor.redColor()
  }
  alert.addAction(UIAlertAction(title: "Ok", style: .Default, handler: { (_) -> Void in
    completionHandler(alert.textFields![0].text!)
  }))
  
  self.presentViewController(alert, animated: true, completion: nil)
}

2).iOS端代码要求:

  // 创建一个webiview的配置项
    let configuretion = WKWebViewConfiguration()

    // 添加一个名称,就可以在JS通过这个名称发送消息:
    // window.webkit.messageHandlers.消息名.postMessage({body: 'xxx'})
    //name需要跟js端的消息名保持一致
    configuretion.userContentController.addScriptMessageHandler(self, name: "AppModel")
    configuretion.userContentController.addScriptMessageHandler(self, name: "AppModel1")

然后实现WKScriptMessageHandler的代理方法:

    // MARK: - WKScriptMessageHandler
    func userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) {
        print(message.body)
        if message.name == "AppModel" {
            print("message name is AppModel")
        }
        
        if message.name == "AppModel1" {
            //TODO:
        }
    }
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