swift 笔记：iOS与JavaScript的交互（一）：UIWebView - 2.2注入JavaScript

Posted 2021-05-19

function sayHelloTo(name) {
  alert(`Hello ${name}`)
}

function sayHelloWithRtnValue (name) {
  return `hello ${name}`
}

extension ViewController: UIWebViewDelegate {
  func webViewDidFinishLoad(_ webView: UIWebView) {
    do {
      // 加载、注入 file.js 
      let path = Bundle.main.path(forResource: "file", ofType: "js")
      let pathURL = URL(fileURLWithPath: path!)
      let jsString = try String(contentsOf: pathURL, encoding: String.Encoding.utf8)
      webviewBrowser.stringByEvaluatingJavaScript(from: jsString)
      
      // 调用其中的方法：
      webviewBrowser.stringByEvaluatingJavaScript(from: "sayHelloTo('Lien')")
      let rtnValue = webView.stringByEvaluatingJavaScript(from: "sayHelloWithRtnValue('Lien')")!
      print("returned value from JavaScript: \(rtnValue)")
    }
    catch {
      print("Fail injecting JavaScript")
    }
  }
}