学习笔记：WKWebView之WKUIDelegate(Swift)

此代理下有8个方法，但其中只有4个是在iOS 8可用，1个在iOS 9添加，剩下3个都是10才可以用，也比较好理解，只做简单的代码展示了。

可在8下使用的四个方法

1、创建一个新的webview时调用：

optionalpublicfuncwebView(_webView:WKWebView,
createWebViewWith configuration:WKWebViewConfiguration, for navigationAction:WKNavigationAction, windowFeatures:WKWindowFeatures)
-> WKWebView?

2、分别在web产生了警告框、确认框、输入框时调用：

optionalpublicfuncwebView(_webView:WKWebView,
runJavaScriptAlertPanelWithMessage message:String, initiatedByFrame frame:WKFrameInfo, completionHandler:
@escaping () -> Swift.Void)

  optionalpublicfuncwebView(_webView:WKWebView,
runJavaScriptConfirmPanelWithMessage message:String, initiatedByFrame frame:WKFrameInfo, completionHandler:
@escaping (Bool) -> Swift.Void)
   
 optionalpublicfuncwebView(_webView:WKWebView,
runJavaScriptTextInputPanelWithPrompt prompt:String, defaultText:String?, initiatedByFrame frame:WKFrameInfo, completionHandler:@escaping
(String?) -> Swift.Void)

3、在webview关闭时调用

optional
public func webViewDidClose(_ webView:
WKWebView)
此关闭操作是有web发起（window.close），而不是由APP本身发起（dismiss或pop）

//MARK: - WKUIDelegate
/**
Description

- parameter webView:           webView description
- parameter message:           message description
- parameter frame:             frame description
- parameter completionHandler: completionHandler必须执行
*/
func webView(_ webView: WKWebView, runJavaScriptConfirmPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping (Bool) -> Void) {
debugPrint("confirm message : \(message)")
debugPrint("class: \(object_getClassName(self))" + #function + "LINE: \(#line)")
completionHandler(true)
}
/**
<#Description#>

- parameter webView:           webView description
- parameter message:           message description
- parameter frame:             frame description
- parameter completionHandler: completionHandler必须执行
*/
func webView(_ webView: WKWebView, runJavaScriptAlertPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping () -> Void) {
debugPrint("class: \(object_getClassName(self))" + #function + "LINE: \(#line)")
debugPrint("webView run alert JS: \(message) ")
completionHandler()
}

func webView(_ webView: WKWebView, runJavaScriptTextInputPanelWithPrompt prompt: String, defaultText: String?, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping (String?) -> Void) {
debugPrint("webView run prompt JS: \(prompt) defaultText:\(defaultText)")
debugPrint("class: \(object_getClassName(self))" + #function + "LINE: \(#line)")

completionHandler("testText")
}
/**
创建一个新的 webView

- parameter webView:          webView description
- parameter configuration:    configuration description
- parameter navigationAction: navigationAction description
- parameter windowFeatures:   windowFeatures description

- returns: return value description
*/
func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration, for navigationAction: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {
debugPrint("class: \(object_getClassName(self))" + #function + "LINE: \(#line)")

return webView
}

/**
9.0 later

- parameter webView: webView description
*/
@available(iOS 9.0, *)
func webViewDidClose(_ webView: WKWebView) {
debugPrint("class: \(object_getClassName(self))" + #function + "LINE: \(#line)")
}
/*
以下方法均为10.0之后
*/

@available(iOS 10.0, *)
func webView(_ webView: WKWebView, shouldPreviewElement elementInfo: WKPreviewElementInfo) -> Bool {
debugPrint("class: \(object_getClassName(self))" + #function + "LINE: \(#line)")
return true
}

@available(iOS 10.0, *)
func webView(_ webView: WKWebView, previewingViewControllerForElement elementInfo: WKPreviewElementInfo, defaultActions previewActions: [WKPreviewActionItem]) -> UIViewController? {
debugPrint("class: \(object_getClassName(self))" + #function + "LINE: \(#line)")
return self

}

@available(iOS 10.0, *)
func webView(_ webView: WKWebView, commitPreviewingViewController previewingViewController: UIViewController) {
debugPrint("class: \(object_getClassName(self))" + #function + "LINE: \(#line)")
}