按下“后退按钮”以返回Web视图

Question

How can I go back one page while in webview? For example: I am on my app in activity and browsing pages in webview, but once I press back button it will exit the app or just goes back in activity instead of the page..

I have done my research and overriding onBackPressed function doesnt work.

@Override
public void onBackPressed() {
    if (myWebView.canGoBack()) {
        myWebView.goBack();
    } else {
        super.onBackPressed();
    }
}

Whole fragment code:

 public class FragmentTwo extends Fragment {


    public FragmentTwo() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment2, container, false);

    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState){

        WebView webView = (WebView) getActivity().findViewById(R.id.webView);

        WebSettings webSettings = webView.getSettings();
        webView.setScrollbarFadingEnabled(false);
        webSettings.setJavaScriptEnabled(true);
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("http://myapp.com");

    }


}

Any suggestions of how to achieve it?

Answer 1

onBackPressed() is method of Activity, not of a Fragment, so this code will never be invoked. If you want to do something on back press, your parent activity must let your fragment know about it - you must implement onBackPressed() in parent activity and in that method you should call fragments' method (or fire event on event bus, or use listeners, callback, whatever).

Also right method name is onCreateView() , not onViewCreated() - this one won't be called either.

Answer 2

Inside of the your OnCreateView:

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        view = inflater.inflate(R.layout.your_layout, container, false);

      webView = (WebView) view.findViewById(R.id.webView);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setWebViewClient(new MyWebViewClient());
        webView.loadUrl(expertsUrl);

        return view;
    }


private class MyWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
    }

Ok! In your MainActivity you will write it:

     @Override
        public void onBackPressed() {
if(yourname_Fragment.webView!=null){
            if (yourname_Fragment.webView.canGoBack()) {
                yourname_Fragment.webView.goBack();
            }
}
        }

yourname_Fragmen.java= This is your nameFragment that content the Webview

webView= The name of your WebView (id)

Now. Inside of your Fragment you have to declare static global variable

public static Webview webView;

NOTE: If you have more than one fragment you have to check if this instance is different of NULL;

And that's it! Good luck!