当WebView应用程序在backgound中加载主页时显示启动画面

Question

我希望在WebView应用程序正在加载背景主页时显示启动画面。 这就是我所做的：

mainactivity.java

public class MainActivity extends AppCompatActivity {

    private static final int REQUEST_WRITE_EXTERNAL_STORAGE = 0;
    private WebView mWebView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mWebView = (WebView) findViewById(R.id.activity_main_webview);

        mWebView.setWebViewClient(new WebViewClient() {
            @Override
            public void onPageFinished(WebView view, String url) {
                // hide splash
                findViewById(R.id.activity_splash).setVisibility(View.GONE);
                // show webview
                mWebView.setVisibility(View.VISIBLE);
            }

            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {

                Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                view.getContext().startActivity(intent);
                return true;
            }
        });

        mWebView.loadUrl("http://www.example.com/");

        // Enable Javascript
        WebSettings webSettings = mWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);

    }

    // Prevent the back-button from closing the app
    @Override
    public void onBackPressed() {
        if (mWebView.canGoBack()) {
            mWebView.goBack();
        } else {
            super.onBackPressed();
        }
    }

}

mainactivity.xml

<?xml version="1.0" encoding="utf-8"?>
<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:background="@color/colorPrimary"
    tools:context="com.myapp.MainActivity">

    <WebView
        android:id="@+id/activity_main_webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone" />

    <ImageView
        android:id="@+id/activity_splash"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@mipmap/splash_logo"
        android:visibility="visible" />
</RelativeLayout>

但是这段代码显示启动画面显示时间不明显...屏幕保持白色一秒钟然后页​​面加载... 如何解决这个问题，任何更好的解决方案都会非常有用。谢谢:)）