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(shè)置WebView屬性，能夠執(zhí)行Javascript腳本
    WebSettings webSettings= webview.getSettings(); // webView: 類WebView的實例
    webSettings.setJavaScriptEnabled(true);
    webSettings.setSupportZoom(true);
    //設(shè)置默認縮放方式尺寸是far
    webSettings.setDefaultZoom(WebSettings.ZoomDensity.FAR);
    //設(shè)置出現(xiàn)縮放工具
    webSettings.setBuiltInZoomControls(true);
    webSettings .setLayoutAlgorithm(LayoutAlgorithm.SINGLE_COLUMN);
    //加載需要顯示的網(wǎng)頁
    webview.loadUrl("http://chabaoo.cn/");
    //設(shè)置Web視圖
    webview.setWebViewClient(new HelloWebViewClient ());
  }
  @Override
  //設(shè)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;
    }
  }
}