WebViewClient.onPageStarted( ) appelé deux fois lors de la spécification inexistante URL via WebView.loadURL()

J'ai eu du mal avec cela, mais je pense que j'ai travaillé autour d'elle. Fondamentalement, j'ai mis un drapeau d'erreur de garder le client de tout traitement de plus de rappels. Le drapeau est remis quand j'ai appeler une méthode de l'activité pour essayer de le charger à nouveau. Voici un exemple de code à partir d'un gist j'ai créé https://gist.github.com/museofwater/6373048

public class AsyncMultiplayerSetupActivity extends Activity {
private static final String TAG = AsyncMultiplayerSetupActivity.class.getName();
public static final String UTF_8 = "UTF-8";
private WebView wvSignin;
private String url = "http://localhost:9000/signin";
private ProgressDialog progressLoadUrl;
private SigninWebViewClient webViewClient;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent intent = getIntent();
registerUser(url);
}
private void registerUser(String url) {
webViewClient = new SigninWebViewClient(getResources().getInteger(R.integer.timeout));
setContentView(R.layout.setup);
wvSignin = (WebView)findViewById(R.id.wvSignin);
wvSignin.getSettings().setJavaScriptEnabled(true);
wvSignin.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
wvSignin.setWebViewClient(webViewClient);
loadUrl(url);
}
private void loadUrl(String url) {
if (!NetworkUtil.checkNetwork(this)) {
setSigninFailureResult();
}
//Show progress
progressLoadUrl =
ProgressDialog.show(this, getString(R.string.CONNECTING_TITLE),
getString(R.string.CONNECTING_MSG));
webViewClient.prepareToLoadUrl();
wvSignin.loadUrl(url);
}
private void setSigninFailureResult() {
setResult(getResources().getInteger(R.integer.RESPONSE_FAILED_CODE));
finish();
}
private void setSigninResult() {    
setResult(getResources().getInteger(R.integer.RESPONSE_OK_CODE));
}
private class SigninWebViewClient extends WebViewClient {
/**
* Timeout for page load in seconds
*/
private int timeout;
private String urlLoading;
boolean pageLoaded = false;
//Flag to instruct the client to ignore callbacks after an error
boolean hasError = false;
private Handler timeoutHandler;
private AlertDialog alertDialog;
private SigninWebViewClient(int timeout) {
this.timeout = timeout;
timeoutHandler = new Handler();
}
//Called by activity before requesting load of a url
private void prepareToLoadUrl() {
this.hasError = false;
this.pageLoaded = true;
this.urlLoading = null;
}
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
if (hasError) {
return;
}
urlLoading = url;
//timeout has expired if this flag is still set when the message is handled
pageLoaded = false;
Runnable run = new Runnable() {
public void run() {
//Do nothing if we already have an error
if (hasError) {
return;
}
//Dismiss any current alerts and progress
dismissProgress();
dismissErrorAlert();
if (!pageLoaded) {
showTimeoutAlert();
}
}
};
timeoutHandler.postDelayed(run, this.timeout*1000);
}
@Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
//Ignore future callbacks because the page load has failed
hasError = true;
dismissProgress();
showServerErrorAlert();
}
@Override
public void onPageFinished(WebView view, String url) {
if (hasError) {
return;
}
pageLoaded = true;
dismissProgress();
dismissErrorAlert();
urlLoading = null;
//Do whatever processing you need to on page load here
}
private void showTimeoutAlert() {
showErrorAlert(R.string.TIMEOUT_TITLE, R.string.TIMEOUT_MSG);
}
private void showServerErrorAlert() {
showErrorAlert(R.string.SERVER_ERROR_TITLE,R.string.SERVER_ERROR_MSG);
}
private void showErrorAlert(int titleResource, int messageResource) {
AlertDialog.Builder builder = new AlertDialog.Builder(AsyncMultiplayerSetupActivity.this);
//Add the buttons
builder.setTitle(titleResource)
.setMessage(messageResource)
.setPositiveButton(R.string.RETRY, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//Try to load url again
loadUrl(urlLoading);
dialog.dismiss();
}
});
builder.setNegativeButton(R.string.CANCEL, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//User cancelled the dialog
setSigninFailureResult();
dialog.cancel();
}
});
//Create the AlertDialog
alertDialog = builder.create();
alertDialog.show();
}
private void dismissProgress() {
if (progressLoadUrl != null && progressLoadUrl.isShowing()) {
progressLoadUrl.dismiss();
}
}
private void dismissErrorAlert() {
if (alertDialog != null && alertDialog.isShowing()) {
alertDialog.dismiss();
}
}
}
}