javascript - 如何使用 wkwebview 从 swift 返回 bool 值到 javascript 函数

Question

这是我在 android 中的功能:

@JavascriptInterface
public boolean GetMobileVersion() {

    return true;
}

这是 JavaScript 中的调用函数:

$(window).load(function () {

    IsCallByMobileApp = false;
    try {
          IsCallByMobileApp = app.GetMobileVersion();/*Is call by android app*/

    } catch (e) {
        IsCallByMobileApp = false;
    }

}

在 iOS 中，我尝试使用 WKWebView 实现相同的方法，但它不起作用:

func userContentController(_ userContentController: WKUserContentController, 
    didReceive message: WKScriptMessage) {

    if(message.name == callbackhandler) {

        webView.evaluateJavaScript("GetMobileVersion();")  { (true, error) in
            guard error == nil else {
                print("there was an error")
                return
            }

            print(Bool(true))
        }
    }
}

谁能告诉我如何将 true 发送到 Javascript 函数？请详细回答我，因为我是 iOS 和 Swift 的新手。

Answer 1

我为此创建了一个 GitHub 项目。 https://github.com/BKRApps/WKWebView-JS .查看更多详细信息。

更新 JavaScript:

 function getMobileVersion(){
        webkit.messageHandlers.VersionHandler.postMessage({})
    }

function receivedMobileVersion(mobileVersion){
        //here you will be getting the mobile version. Then execute the logic. 
        // i have added this only to cross check the version. you don't need to add this.

      if(mobileVersion === true) { 
      webkit.messageHandlers.VerifyHandler.postMessage({version:mobileVersion})
    }
 }

getMobileVersion()

将以下代码添加到 WKWebView 配置中:

 configuration.userContentController.add(self, name: "VersionHandler")
// i have added this only to cross check the version. you don't need to add this.
 configuration.userContentController.add(self, name: "VerifyHandler")

更新 WKScriptMessageHandler 委托(delegate):

func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
    switch message.name {
    case "VersionHandler":
        let mobileVersion = true //write the version logic and send the true or false.
        let sendMobileVersionScript = "receivedMobileVersion(\(mobileVersion))"
        self.wkWebView?.evaluateJavaScript("\(sendMobileVersionScript)", completionHandler: { (any, error) in
                            print("hello")
        })
    case "VerifyHandler":
        print(message.body) // i have added this only to cross check the version. you 
    default:
        break;
    }
}

了解更多信息:http://igomobile.de/2017/03/06/wkwebview-return-a-value-from-native-code-to-javascript/