WebView在加载完成之前显示loading图标

1.引入GifView.jar，编写xml文件（为了让loading居中，不得不尝试了很多方法，结果就添加了好几个嵌套的layout才实现，如果有更简洁的方法，请博友告知）：

<LinearLayout 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:background="@color/white"    tools:context="com.doorknocker.MainActivity"    android:orientation="vertical" >    <LinearLayout        android:id="@+id/ll_web_view_container"        android:layout_width="match_parent"        android:layout_height="match_parent" >        <RelativeLayout             android:id="@+id/rl_loading"            android:layout_width="match_parent"            android:layout_height="match_parent" >            <LinearLayout                 android:layout_width="match_parent"                android:layout_height="wrap_content"                android:orientation="vertical"                android:gravity="center_horizontal"                android:layout_centerVertical="true" >                <com.ant.liao.GifView android:id="@+id/gv_loading"                      android:layout_height="wrap_content"                     android:layout_width="wrap_content"                      android:enabled="false" />            </LinearLayout>        </RelativeLayout>                <WebView            android:id="@+id/wv_right_content"            android:layout_width="match_parent"            android:layout_height="match_parent" />    </LinearLayout></LinearLayout>

2.代码：

View rootView = inflater.inflate(R.layout.fragment_right, null);wv_right_content = (WebView) rootView.findViewById(R.id.wv_right_content);gv_loading = (GifView) rootView.findViewById(R.id.gv_loading);rl_loading = (RelativeLayout) rootView.findViewById(R.id.rl_loading);gv_loading.setGifImage(R.drawable.loading_gif);// 得到底部菜单栏高度bottomTabHeight = UIUtils.getBottomTabHeight(mActivity);// WebView的高度是屏幕整体高度减去状态栏高度，再减去顶部菜单条高度，再减去底部Tab高度LinearLayout mLayout = (LinearLayout) rootView.findViewById(R.id.ll_web_view_container);LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);params.height = UIUtils.getScreenHeight(mActivity) - UIUtils.getStatusBarHeight() - bottomTabHeight;mLayout.setLayoutParams(params);WebSettings webSettings = wv_right_content.getSettings();webSettings.setJavaScriptEnabled(true);webSettings.setSupportZoom(true);webSettings.setBuiltInZoomControls(true);//设置Web视图 wv_right_content.setWebViewClient(new WebViewClient() {    @Override    public boolean shouldOverrideUrlLoading(WebView view, String url) {         view.loadUrl(url);        // 记住当前的URL        currentRightUrl = url;        // 由当前的WebView处理跳转        return true;    }    @Override    public void onPageStarted(WebView view, String url, Bitmap favicon) {        rl_loading.setVisibility(View.VISIBLE);        wv_right_content.setVisibility(View.GONE);    }    @Override    public void onPageFinished(WebView view, String url) {        super.onPageFinished(view, url);        rl_loading.setVisibility(View.GONE);        wv_right_content.setVisibility(View.VISIBLE);    }});return rootView;