webView.addJavascriptInterface(new WebAppInterface(this), "android");
interface WebAppInterface {
showToast(toast: string) : any;
}
declare var android: WebAppInterface;
var button = document.getElementById('button');
button.onclick = ()=>android.showToast('Hello Android!');
참고 :: https://stackoverflow.com/questions/41220743/call-android-method-from-typescript