//声明WebView对象

private WebView webView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

//隐藏标题栏

this.requestWindowFeature(Window.FEATURE_NO_TITLE);

//隐藏状态栏

this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

//实例化webView(网络视图)对象

webView = new WebView(this);

setContentView(R.layout.activity_main);

webView = (WebView) findViewById(R.id.web_view);

webView.setWebViewClient(new WebViewClient(){});

//设置webView属性，能够执行Javascript代码

webView.getSettings().setJavaScriptEnabled(true);

WebSettings settings = webView.getSettings();

//设定支持viewport

settings.setUseWideViewPort(true);

//打开页面时，自适应屏幕

settings.setLoadWithOverviewMode(true);

//设定支持缩放

settings.setSupportZoom(true);

settings.setBuiltInZoomControls(true);

//默认缩放尺寸

settings.setDefaultZoom(WebSettings.ZoomDensity.FAR);

//隐藏缩放图标

settings.setDisplayZoomControls(false);

//优先使用缓存

settings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);

webView.setWebViewClient(new WebViewClient(){

@Override

public boolean shouldOverrideUrlLoading(WebView view, String url){

//根据传入的参数再去加载新的网页

view.loadUrl(url);

//表示当前WebView可以处理打开新网页的请求，不用借助系统浏览器

return true;

}

});

//加载需要显示的页面(互联网)

webView.loadUrl("

        //加载需要显示的页面(本地assets文件夹下)

//        webView.loadUrl("file:///android_asset/test1.html");

}

@Override

/**

* 设置回退,返回上个页面而不是直接退出

* 覆盖Activity类的onKeyDown(int keyCoder,KeyEvent event)方法 

*/

public boolean onKeyDown(int keyCode, KeyEvent event) {

if((keyCode == KeyEvent.KEYCODE_BACK) && webView.canGoBack()){

webView.goBack();

return true;

}

else{

return super.onKeyDown(keyCode, event);

}

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

    <WebView

        android:id="@+id/web_view"

android:layout_width="match_parent"

android:layout_height="wrap_content" />

    

</LinearLayout>