public?class?MainActivity?extends?AppCompatActivity?{
private?WebView?wv;
????private?ProgressDialog?pd;
????@Override
????protected?void?onCreate(Bundle?savedInstanceState)?{
????????super.onCreate(savedInstanceState);
????????setContentView(R.layout.activity_main);
????????init();
????}
????private?void?init()?{
????????wv=(WebView)findViewById(R.id.webView);
????????wv.loadUrl("http://www.bilibili.com");
????????//使得網(wǎng)頁從WebView中打開，而不是跳轉(zhuǎn)
????????wv.setWebViewClient(new?WebViewClient(){
????????????@Override
????????????public?boolean?shouldOverrideUrlLoading(WebView?view,?String?url)?{
????????????????view.loadUrl(url);
????????????????return?true;

????????????}
????????});
????????//判斷頁面加載過程
????????wv.setWebChromeClient(new?WebChromeClient(){
????????????@Override
????????????public?void?onProgressChanged(WebView?view,?int?newProgress)?{
????????????????if(newProgress==100){
????????????????????closeDialog();
????????????????}else?{
????????????????????openDialog(newProgress);
????????????????}
????????????}
????????????private?void?openDialog(int?newProgress)?{
????????????????//如果對話框等于空，也就是沒有對話框
????????????????if(pd==null){
????????????????????//設(shè)定一個新的對話框
????????????????????pd=new?ProgressDialog(MainActivity.this);
????????????????????//設(shè)置標題
????????????????????pd.setTitle("加載中。。。");
????????????????????pd.setIcon(R.mipmap.ic_launcher);
????????????????????//設(shè)置對話框進度條樣式，設(shè)置為橫向
????????????????????pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
????????????????????//設(shè)置進度，隨刷新進度改變
????????????????????pd.setProgress(newProgress?);
????????????????????pd.show();

????????????????}else{
????????????????????pd.setProgress(newProgress?);
????????????????}
????????????}
????????????private?void?closeDialog()?{
????????????????if(pd!=null&&pd.isShowing()){
????????????????????pd.dismiss();
????????????????????pd=null;
????????????????}
????????????}
????????});
????}
????//改寫前進與后退的邏輯,使得物理返回按鈕默認為上一頁面
????public?boolean?onKeyDown(int?keyCode,?KeyEvent?event)?{
????????if?(keyCode==KeyEvent.KEYCODE_BACK){
????????????if(wv.canGoBack()){
????????????????wv.goBack();
????????????????return?true;
????????????}else?{
????????????????System.exit(0);
????????????}
????????}
????????return?super.onKeyDown(keyCode,?event);
????}
}

詳細一點你這個,搞不懂啊