public class MainActivity extends Activity {  private WebView webview;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    webview = (WebView) findViewById(R.id.webview);    //設置WebView屬性，能夠執行Javascript腳本    WebSettings webSettings= webview.getSettings(); // webView: 類WebView的實例    webSettings.setJavaScriptEnabled(true);    webSettings.setSupportZoom(true);    //設置默認縮放方式尺寸是far    webSettings.setDefaultZoom(WebSettings.ZoomDensity.FAR);    //設置出現縮放工具    webSettings.setBuiltInZoomControls(true);    webSettings .setLayoutAlgorithm(LayoutAlgorithm.SINGLE_COLUMN);    //加載需要顯示的網頁    webview.loadUrl("http://m.survivalescaperooms.com/");    //設置Web視圖    webview.setWebViewClient(new HelloWebViewClient ());  }  @Override  //設置回退  //覆蓋Activity類的onKeyDown(int keyCoder,KeyEvent event)方法  public boolean onKeyDown(int keyCode, KeyEvent event) {    if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack()) {      webview.goBack(); //goBack()表示返回WebView的上一頁面      return true;    }    return false;  }  //Web視圖  private class HelloWebViewClient extends WebViewClient {    @Override    public boolean shouldOverrideUrlLoading(WebView view, String url) {      view.loadUrl(url);      return true;    }  }}