【Android基础知识】WebView基本用法

来源：互联网发布：linux trap 编辑：程序博客网时间：2024/06/06 03:44

Android WebView用来加载网页，显示网页内容。

1.在布局文件中添加WebView组件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.example.webviewdemo.MainActivity" >    <WebView        android:id="@+id/webView1"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true" /></RelativeLayout>

2.在AndroidManifest.xml文件中添加访问互联网的权限

<uses-permission android:name="android.permission.INTERNET"/>

3.使用WebView

public class MainActivity extends Activity {private String uri = "http://www.baidu.com";private WebView webView;private ProgressDialog progressDialog;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);      /*  //通过intent跳转        Uri mUri = Uri.parse(uri);        Intent intent = new Intent(Intent.ACTION_VIEW,mUri);        startActivity(intent);*/        init();    }    private void init(){    webView = (WebView)findViewById(R.id.webView1);    /*//webView加载本地资源    webView.loadUrl("file:///android_asset/t.html");*/    //webView加载外部资源    webView.loadUrl(uri);    //覆盖WebView默认通过第三方或者是浏览器打开网页的行为，使得网页可以在WebView中打开,需要internet权限    webView.setWebViewClient(new WebViewClient(){@Overridepublic boolean shouldOverrideUrlLoading(WebView view, String url) {//返回值是true的时候控制网页在WebView中去打开，false则是在第三方打开view.loadUrl(url);return true;//return super.shouldOverrideUrlLoading(view, url);}        });    //启用支持JavaScript    WebSettings settings = webView.getSettings();    settings.setJavaScriptEnabled(true);    //WebView 加载页面优先使用缓存加载    settings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);    //判断页面的加载过程，进度    webView.setWebChromeClient(new WebChromeClient(){@Overridepublic void onProgressChanged(WebView view, int newProgress) {//newProgress 1-100之间的整数if(newProgress == 100){//网页加载完毕closeDialog();}else{//网页正在加载，打开ProgressDialogopenDialog(newProgress);}}    private void closeDialog(){    if(progressDialog != null && progressDialog.isShowing()){    progressDialog.dismiss();    progressDialog = null;    }    }    private void openDialog(int progress){    if(progressDialog == null){    progressDialog = new ProgressDialog(MainActivity.this);    progressDialog.setTitle("正在加载");    progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);    progressDialog.setProgress(progress);    progressDialog.show();    }else{    progressDialog.setProgress(progress);    progressDialog.show();    }    }    });    }    @Override    public boolean onKeyDown(int keyCode, KeyEvent event) {    if(keyCode == KeyEvent.KEYCODE_BACK){    Toast.makeText(this, "back", Toast.LENGTH_SHORT).show();    if(webView.canGoBack()){    webView.goBack();    return true;    }else{    System.exit(0);    }    }    return super.onKeyDown(keyCode, event);    }}

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