声明具有INTERNET权限
<uses-permission android:name= "android.permission.INTERNET" />
private String url="http://stareblankly.cn";
private WebView webView ;
private ProgressDialog progressDialog ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout. activity_main);
Uri uri=Uri. parse(url);
Intent intent= new Intent(Intent.ACTION_VIEW,uri);
startActivity(intent);
init();
}
private void init() {
webView=(WebView) findViewById(R.id. webView);
webView.loadUrl( "file:///android_asset/az.html" ); //加载本地资源
webView.loadUrl( "http://www.baidu.com"); //加载网络资源
//覆盖webview默认通过第三方或者是系统浏览器打开网页的行为，使得网页可以在 webview中打开。
webView.setWebViewClient( new WebViewClient(){
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// 返回值为true的时候控制网页在 webview中打开，为false网络则在系统或者第三方浏览器中打开
view.loadUrl(url);
return true ;
}
//webviewClient帮助webview去处理一下页面控制和请求通知
});
//启用支持JS
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);
webView.setWebChromeClient( new WebChromeClient(){
@Override
public void onProgressChanged(WebView view, int newProgress) {
if(newProgress==100){
//网页加载完毕
closeDialog();
} else{
//网页正在加载,打开progressDialog
openDialog(newProgress);
}
}
private void closeDialog() {
if(progressDialog !=null&&progressDialog.isShowing()){
progressDialog.dismiss();
progressDialog=null ;
}
}
private void openDialog(int newProgress) {
if(progressDialog ==null){
progressDialog=new ProgressDialog(MainActivity.this );
progressDialog.setProgressStyle(progressDialog .STYLE_HORIZONTAL);
progressDialog.setProgress(newProgress);
progressDialog.show();
} else{
progressDialog.setProgress(newProgress); //刷新进度
}
}
});
}
//改写物理按钮--返回按钮的逻辑
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode==KeyEvent.KEYCODE_BACK){
if(webView .canGoBack()){
webView.goBack(); //返回上一页
return true ;
} else{
System. exit(0); //退出程序
}
}
return super .onKeyDown(keyCode, event);
}