native 端
初始化 wkwebview，设置 message handler
webView = WKWebView.init() let usecc = self.webView.configuration.userContentController usecc.add(self, name: "testecho")实现
WKScriptMessageHandler协议extension ViewController: WKScriptMessageHandler { func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) { mylog("\(self.sendCount) call native , message is \(message.name),") } }执行JS 代码
//jsStr = "echo(\"wordword\")" self.webView.evaluateJavaScript(jsStr) { (result, err) in self.mylog("\(self.sendCount) \(jsStr.count) bytes callback, result: \(result), err: \(err)") }前端
<!DOCTYPE html> <html> <script type="text/javascript"> function echo(str) { console.log(str); window.webkit.messageHandlers.testecho.postMessage(str); } </script> <body> <input type="button" onClick="echo('toast clicked')" value="toast"> <input type="button" onClick="echo('alert clicked')" value="Alert"> </body> </html>
分析
native 端注册了 testecho 的messageHandler，所以 JS 可以通过 window.webkit.messageHandlers.testecho.postMessage 来回调客户端，和文档中说的一样。
Adding a script message handler with name name causes the JavaScript function window.webkit.messageHandlers.name.postMessage(messageBody) to be defined in all frames in all web views that use the user content controller.