android - WebView reloading when Fragment in ViewPager is retained form BackStack

Question

Here is a code for a basic Fragment which contains a WebView.
WebFragment.java

public class WebFragment extends Fragment {
String TAG = "WebFragment";
private WebView webView;
private String currentUrl = "http://www.google.com";

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    return inflater.inflate(R.layout.webview_layout, null);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    webView = (WebView) getView().findViewById(R.id.helloWebview);
    initWebView();
    webView.loadUrl(currentUrl);
}

@SuppressLint("SetJavaScriptEnabled")
private void initWebView() {
    webView.getSettings().setJavaScriptEnabled(true);
    webView.addJavascriptInterface(new JavaScriptInterface(), "HTMLOUT");
    webView.setWebViewClient(new WebViewClient() {
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            Log.e(TAG, "Loding...");
            super.onPageStarted(view, url, favicon);
        }
    });
}

class JavaScriptInterface {
    public void showHTML(String html) {
    }
}
}

I have 2 more basic fragments also(which doesn't have WebView). Then I put all these 3 Fragments in ViewPager(WebFragment, Fragment1 and Fragment2respectively) using FragmentAdapter. And I added android:configChanges="orientation|screenSize" in AndroidManifest.xml(So WebView will not realod on configration change).
Now my problem is, While running app I changed the 1st page (WebFragmet) of ViewPager to 2nd page(Fragment1) and again I came back to 1st page. So no problem WebFragment is as it is.

Now again I changed the ViewPager like this WebFragment-->Fragment1-->Fragment2 and came back to 1st page by reversing the direction of above action. But at that time I saw the WebView in WebFragment is reloading.

And one more problem, whenever the WebView started loading I can see 2 log entry like.

WebFragment Loading...
WebFragment Loading...

So my question is :
1) How can I prevent WebView reloading when the WebFragment is retained from BackStack?
2) Why here WebView loading twice?

Just see this question and help me(Prevent WebView reloads in FragmentPagerAdapter?).

Answer 1

In your main activity where you have defined viewpager

after the declaration of viewpager like this line : ViewPager viewpager = (ViewPager) findViewById(R.id.pager);

add this line :

viewpager.setOffscreenPageLimit(2);

This will prevent your fragment from recreated upto swipe of two screens,so when you will return from 3rd page to 1st page in viewpager,your webview will not reload.