Tengo en el siguiente código la barra de progreso trabajando en la carga de la primera página. después de hacer clic en otros enlaces, la barra de progreso no se muestra?

Si alguien puede decirme cómo cambiar este código para que la barra de progreso funcione en todas las cargas?

Gracias

André.

public class Android_Activity extends Activity {
WebView webview;

@Override
protected void onSaveInstanceState(Bundle outState) {
    WebView webview = (WebView) findViewById(R.id.webview);
    webview.saveState(outState);
}   

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

    // set the main content view
    setContentView(R.layout.main);

    // check if an instance is stored and so restore it
    if (savedInstanceState != null){
        ((WebView)findViewById(R.id.webview)).restoreState(savedInstanceState);
    }

    final ProgressDialog progressBar = ProgressDialog.show(this, getString(R.string.progress_title),
            getString(R.string.progress_msg));

    webview = (WebView)findViewById(R.id.webview);
    webview.setHttpAuthUsernamePassword(getString(R.string.kdg_host),
            getString(R.string.kdg_realm),
            getString(R.string.kdg_user_name),
            getString(R.string.kdg_password)
            );
    //webview.setWebViewClient(new myWebViewClient());
    webview.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
    webview.getSettings().setRenderPriority(RenderPriority.HIGH);
    webview.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
    webview.getSettings().setAllowFileAccess(true);
    webview.getSettings().setJavaScriptEnabled(true);

    webview.setWebViewClient(new WebViewClient() {
        public void onPageStarted(WebView view, String url) {
            if (!progressBar.isShowing()) {
                progressBar.show();
            }
        }           
        public void onPageFinished(WebView view, String url) {
            //super.onPageFinished(view, url);
            if (progressBar.isShowing()) {
                progressBar.dismiss();
            }
        }           
    });

    webview.loadUrl(getString(R.string.base_url));
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack()) {
        webview.goBack();
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

private class myWebViewClient extends WebViewClient {   
    @Override       
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        boolean error = false;          

        // check if it's an MAILTO URL
        if(url.substring(0, 6).equalsIgnoreCase("mailto")){
            Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
            emailIntent .setType("plain/text");
            emailIntent .putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{url.substring(7)});
            startActivity(Intent.createChooser(emailIntent, "Send mail..."));   
            return true;
        }
        // check if it's an EXT:// (Call Web Browser)
        else if(url.substring(0, 6).equalsIgnoreCase("ext://")){
            Uri uriUrl = Uri.parse(url.substring(6));
            Intent launchBrowser = new Intent(Intent.ACTION_VIEW, uriUrl); 
            startActivity(launchBrowser);   
            return true;
        }               
        // check if it's an RTSP URL
        else if(url.substring(0, 4).equalsIgnoreCase("rtsp")){
            Uri uri = Uri.parse(url);
            Intent intent = new Intent(Intent.ACTION_VIEW, uri);
            startActivity(intent);
            return true;
        }
        // else if it's an MP4 file link
        else if(url.endsWith(".mp4")){
            Uri uri = Uri.parse(url);
            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.setDataAndType(uri, "video/mp4");
            startActivity(intent);
            return true;
        }
        // else if it's a 3GP file link
        else if(url.endsWith(".3gp")){
            Uri uri = Uri.parse(url);
            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.setDataAndType(uri, "video/3gp");
            startActivity(intent);
            return true;
        }
        // else if it's a MP3 file link
        else if(url.endsWith(".mp3")){
            Uri uri = Uri.parse(url);
            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.setDataAndType(uri, "audio/mp3");
            startActivity(intent);
            return true;
        }               
        // else if it's a page URL
        else{
            URL Url;
            try {
                Url = new URL(url);
                HttpURLConnection httpURLConnection = (HttpURLConnection) Url
                        .openConnection();
                int response = httpURLConnection.getResponseCode();
                if ((response >= 200)&&(response < 400))
                    //view.loadUrl(url);
                    error = false;
                else
                    error = true;
            } catch (Exception e) {
                error = true;
            }
        }

        // if an error occurred
        if (error) {
            showErrorDialog();
        }

        view.loadUrl(url);          
        return true;                    
    }
}   

@Override
public void onResume() {
    super.onResume();
    webview.reload();
}   

public void onReceivedError(WebView view, int errorCode,
        String description, String failingUrl) {
    showErrorDialog();
}

public void showErrorDialog(){
    AlertDialog alertDialog = new AlertDialog.Builder(this).create();
    alertDialog.setTitle(getString(R.string.error_title));
    alertDialog.setMessage(getString(R.string.error_msg));
    alertDialog.setButton(getString(R.string.ok_btn),
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog,
                        int which) {
                }
            });
    alertDialog.show();
}
}