在片段视图中显示webview的进度条

Question

我试图在网页出现或加载之前显示进度条。我已经在PlanetFragment的onCreateView方法中声明了进度条，它扩展了片段我已经删除了网页的听众。但是进度条并没有出现我写的任何代码。请帮忙

这是我的MainActivity

public class MainActivity extends Activity {

private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;

private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String[] mPlanetTitles;

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

    mTitle = mDrawerTitle = getTitle();
    mPlanetTitles = getResources().getStringArray(R.array.planets_array);
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mDrawerList = (ListView) findViewById(R.id.left_drawer);

    // set a custom shadow that overlays the main content when the drawer
    // opens
    mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,
            GravityCompat.START);
    // set up the drawer's list view with items and click listener
    mDrawerList.setAdapter(new ArrayAdapter<String>(this,
            R.layout.drawer_list_item, mPlanetTitles));
    mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

    // enable ActionBar app icon to behave as action to toggle nav drawer
    getActionBar().setDisplayHomeAsUpEnabled(true);
    getActionBar().setHomeButtonEnabled(true);

    // ActionBarDrawerToggle ties together the the proper interactions
    // between the sliding drawer and the action bar app icon
    mDrawerToggle = new ActionBarDrawerToggle(this, /* host Activity */
    mDrawerLayout, /* DrawerLayout object */
    R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
    R.string.drawer_open, /* "open drawer" description for accessibility */
    R.string.drawer_close /* "close drawer" description for accessibility */
    ) {
        public void onDrawerClosed(View view) {
            getActionBar().setTitle(mTitle);
            invalidateOptionsMenu(); // creates call to
                                        // onPrepareOptionsMenu()
        }

        public void onDrawerOpened(View drawerView) {
            getActionBar().setTitle(mDrawerTitle);
            invalidateOptionsMenu(); // creates call to
                                        // onPrepareOptionsMenu()
        }
    };
    mDrawerLayout.setDrawerListener(mDrawerToggle);

    if (savedInstanceState == null) {
        selectItem(0);
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main, menu);
    return super.onCreateOptionsMenu(menu);
}

/* Called whenever we call invalidateOptionsMenu() */
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    // If the nav drawer is open, hide action items related to the content
    // view
    boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
    menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
    return super.onPrepareOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // The action bar home/up action should open or close the drawer.
    // ActionBarDrawerToggle will take care of this.
    if (mDrawerToggle.onOptionsItemSelected(item)) {
        return true;
    }
    // Handle action buttons
    switch (item.getItemId()) {
    case R.id.action_websearch:
        // create intent to perform web search for this planet
        Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
        intent.putExtra(SearchManager.QUERY, getActionBar().getTitle());
        // catch event that there's no activity to handle intent
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        } else {
            Toast.makeText(this, R.string.app_not_available,
                    Toast.LENGTH_LONG).show();
        }
        return true;
    default:
        return super.onOptionsItemSelected(item);
    }
}

/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements
        ListView.OnItemClickListener {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        selectItem(position);
    }
}

private void selectItem(int position) {
    // update the main content by replacing fragments
    Fragment fragment = new PlanetFragment();
    Bundle args = new Bundle();
    args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position);
    fragment.setArguments(args);

    FragmentManager fragmentManager = getFragmentManager();
    fragmentManager.beginTransaction()
            .replace(R.id.content_frame, fragment).commit();

    // update selected item and title, then close the drawer
    mDrawerList.setItemChecked(position, true);
    setTitle(mPlanetTitles[position]);
    mDrawerLayout.closeDrawer(mDrawerList);
}

@Override
public void setTitle(CharSequence title) {
    mTitle = title;
    getActionBar().setTitle(mTitle);
}

/**
 * When using the ActionBarDrawerToggle, you must call it during
 * onPostCreate() and onConfigurationChanged()...
 */

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    // Sync the toggle state after onRestoreInstanceState has occurred.
    mDrawerToggle.syncState();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    // Pass any configuration change to the drawer toggls
    mDrawerToggle.onConfigurationChanged(newConfig);
}

/**
 * Fragment that appears in the "content_frame", shows a planet
 */
public static class PlanetFragment extends Fragment {
    public static final String ARG_PLANET_NUMBER = "planet_number";

    public PlanetFragment() {
        // Empty constructor required for fragment subclasses
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_planet,
                container, false);
        int i = getArguments().getInt(ARG_PLANET_NUMBER);
        String planet = getResources()
                .getStringArray(R.array.planets_array)[i];

        int imageId = getResources().getIdentifier(
                planet.toLowerCase(Locale.getDefault()), "drawable",
                getActivity().getPackageName());

        final WebView webview = ((WebView) rootView
                .findViewById(R.id.image));

        final ProgressBar progressbar = ((ProgressBar) rootView
                .findViewById(R.id.progressbar));





        webview.getSettings().setJavaScriptEnabled(true);
        final PlanetFragment activity = this;


        webview.setWebViewClient(new WebViewClient() {
            @Override
            public void onPageFinished(WebView view, String url) {

                webview.loadUrl("javascript:document.getElementsByClassName('header')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('icon-anon')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('search')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('wh_ad')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('cse_x')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('wh_search')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('wh_ad')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('wh_ad')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('footer_random_button')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('mw-mf-page-left')[0].style.display=\"none\";");
                webview.loadUrl("javascript:document.getElementsByClassName('mw-mf-viewport')[0].style.display=\"none\";");

                webview.getSettings().setJavaScriptEnabled(false);

            }
        });

        webview.loadUrl(planet);
        getActivity().setTitle(planet);
        return rootView;
    }
}

}

这是我的xml布局：

<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"
tools:context=".MainActivity" >

<ProgressBar
    android:id="@+id/progressbar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginRight="5dp" />

<WebView
    android:id="@+id/image"
    android:layout_width="wrap_content"
    android:layout_height="match_parent" />

Answer 1

这样的事情应该有效。我没有测试过它（现在没有编辑器）。解决方案是隐藏webview并在适当的时间显示它。

 webview.setWebViewClient(new WebViewClient() {
        @Override
        public void onPageFinished(WebView view, String url) {
           view.setVisibility(View.VISIBLE);
           //you might need this
           view.bringToFront();
        }
        @Override
        public void onPageStarted(WebView view, String url,  Bitmap favicon) {
           view.setVisibility(View.GONE);//hide the webview that will display your dialog
        }
    });

Answer 2

这是因为ProgressBar＆＃34;＆＃34;＆＃34; under＆＃34; xml中的WebView（意味着在xml中声明的第一个小部件将是最深层次的小部件，小部件被堆叠）。

尝试将ProgressBar放在xml中，并在必要时隐藏它，如下所示：

<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"
 tools:context=".MainActivity" >

 <WebView
      android:id="@+id/image"
      android:layout_width="wrap_content"
      android:layout_height="match_parent" />

 <ProgressBar
      android:id="@+id/progressbar"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_marginRight="5dp" />

</RelativeLayout>    

目前WebView停留在ProgressBar

前面