javascript - 使用 wkwebview 从 javascript 调用返回值的 swift 函数

Question

我想从将 device id 返回给脚本的 java 脚本代码中调用一个 swift 函数，我已经添加了当前使用的代码。请告知如何从 swift 函数将值返回给 java 脚本，在此先感谢

代码片段:

     super.viewDidLoad()
    {
    self.webView = WKWebView()
    let preferences = WKPreferences()
    preferences.javaScriptEnabled = true
    let configuration = WKWebViewConfiguration()
    configuration.preferences = preferences
    configuration.userContentController = contentController
    configuration.userContentController.addScriptMessageHandler(self,name: "interOp")
    self.webView = WKWebView(frame: self.view.frame, configuration: configuration)
    print(self.view.frame)
    self.view = self.webView
    webView!.navigationDelegate = self
    let url = NSURL(string:"http://softence.com/devTest/vb_ios.html")
    let req = NSURLRequest(URL:url!)
    self.webView!.loadRequest(req)

    }

// did receivescript message is working fine
func userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage)
{
    let sentData = message.body as! NSDictionary
    print(sentData)
    if sentData["name"] as! String == "DeviceInfo"
    {
        self.DeviceInfo()
    }
}
// i want to return the following device info to javascript
func DeviceInfo() -> String
{
let dict = NSMutableDictionary()
    dict.setValue(UIDevice.currentDevice().model, forKey: "model")
    dict.setValue(UIDevice.currentDevice().name, forKey: "name")
    dict.setValue(UIDevice.currentDevice().systemVersion, forKey: "system_version")
    return String(dict)
}

Answer 1

尝试查看 WKWebView 上的 evaluateJavaScript(_:, completionHandler:) 函数，如 here 所述

要使用它，您的 DeviceInfo 函数应该定义您要执行的完整的 JavaScript 字符串。

例如，如果你有一个像这样定义的 JavaScript 函数:

showDeviceInfo(model, name, system_version) {

}

然后你的 DeviceInfo 函数看起来像这样:

func deviceInfo() {
    let model = UIDevice.currentDevice().model
    let name = UIDevice.currentDevice().name
    let systemVersion = UIDevice.currentDevice().systemVersion

    let javaScriptString = "showDeviceInfo(\(model), \(name), \(systemVersion));" //string your JavaScript string together from the previous info...and no...it aint pretty :)
    webView.evaluateJavaScript(javaScriptString, completionHandler: nil)
}

您还可以从 DeviceInfo 函数返回 javaScriptString，然后在您的 userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) 中调用它，重要的是:

1. 您需要定义要执行的整个 JavaScript 字符串
2. 你需要调用evaluateJavaScript

希望对你有帮助。