你需要像这样处理Android硬按钮：

You need to handle Android hard button like this:

首先导入依赖项：

import { AndroidApplication, AndroidActivityBackPressedEventData } from "application";
import * as application from "application";

然后添加以下代码：

application.android.on(AndroidApplication.activityBackPressedEvent, (data: AndroidActivityBackPressedEventData) => {
  data.cancel = true; // prevents default back button behavior
  console.log("webview can go back "+this.webView.canGoBack);
  if (webView.canGoBack) //if webview can go back
      webView.goBack();
  else
      this.router.backToPreviousPage();
});