I know the following is probably not the best practice and not recommended to do.
I have an AsyncTask that sends data to server. The whole process that i need to do includes 4 web calls using this AsyncTask in quick succession.
I understand that with AsyncTask you must start and stop the ProgressDialog in OnPreExecute and OnPostExecute. I do normally do this.
The problem is that i call 4 AsyncTask in a row one after another, so i don't want 4 Progress dialogs repeating one after another.
I use AsyncTask.execute().get(), so they are called sequentially.
I call these AsyncTasks in a loop from the optionsMenu. What i am trying to do is set up a global ProgressDialog that i can start in the optionsMenu before the loop and cancel it after the loop.
The problem is that it doesn't show. I thought it may be because it needs to run on the UI thread so i placed it inside a Handler, but still no luck.
How can I show the progressdialog from the optionsMenu?
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menuclientassessment, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.sendclientassessment:
new Handler(Looper.getMainLooper()).post(new Runnable() {
#Override
public void run() {
progressDialog2 = new ProgressDialog(ClientAssessmentActivity.this);
progressDialog2.setTitle("Connecting to Server");
progressDialog2.setMessage("Sending the assessment to server...");
progressDialog2.setIndeterminate(true);
try {
progressDialog2.show();
} catch(Exception e){
//ignore
}
}
});
for(int i = 0; i < arr.size(); i++) {
String [] params = new String[6];
AssessmentScore as = null;
as = arr.get(i);
params[0] = clientID;
params[1] = carerID;
params[2] = comments.getText().toString();
DateTime now = new DateTime();
DateTimeFormatter df = DateTimeFormat.forPattern("yyyy-MM-dd'T'H:mm");
String formattedNowTime = df.print(now);
params[3] = formattedNowTime;
params[4] = as.getElementID();
params[5] = as.getValue();
AsyncSendAssessment asa = null;
asa = new AsyncSendAssessment();
try {
asa.execute(params).get();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}//end of loop
new Handler(Looper.getMainLooper()).post(new Runnable() {
#Override
public void run() {
try {
progressDialog2.dismiss();
} catch(Exception e) {
//ignore
}
}
});
return true;
default:
return super.onOptionsItemSelected(item);
}
}
Have the progress dialog be a class variable, then instantiate it when you create the activity. That way you can access it anywhere in the application.
Create your dialog to be a class extending the class Dialog. For eg. - TestDialog. Then create a Util class with common functions using the dialog.
public class TestDialog extends Dialog {
}
Util:
public class TestDialogUtil {
public static TestDialog processingDialog;
public static void createProcessingDialog();
public static void dismissProcessingDialog();
}
Then in any of your Activities call TestDialogUtil.createProcessingDialog or TestDialogUtil.dismissProcessingDialog. You won't get extra dialogs getting created. Create a new Dialog only when processingDialog is not null.
Related
I've got an app that makes API calls when the user logs in, I've got two classes, one that Pushes to the API and one that Pulls from it. I've also got an asyncTask on my LogIn Activity which handles the network connection. When the network connection starts I have a view switcher to switch the view to a progress loader and a textview, the textview is used to display stuff like "Connecting", "Downloading Data", ect.
The problem is my API Push and Pull methods are stored in different classes and the LogIn AsyncTask simply calls them, it all works except for updating the TextView to let the user know the progress.
In the LogIn activity, I have this method, which changes the textview info to whichever number is passed to it.
public void updateProgress(int i) {
switch (i) {
case 0:
loadInfo.setText(R.string.log_in_thread_Connecting);
break;
case 1:
loadInfo.setText(R.string.log_in_thread_Connected);
break;
case 2:
loadInfo.setText(R.string.log_in_Thread_Sending_Data);
break;
case 3:
loadInfo.setText(R.string.log_in_thread_Response);
break;
case 4:
loadInfo.setText(R.string.log_in_web_connecting);
break;
case 5:
loadInfo.setText(R.string.log_in_web_connected);
break;
case 6:
loadInfo.setText(R.string.log_in_web_user_data_download);
break;
case 7:
loadInfo.setText(R.string.log_in_web_user_data_downloaded);
break;
case 8:
loadInfo.setText(R.string.log_in_web_device_data_upload);
break;
}
}
This works if i'm calling it from the AsyncTask from the LogIn Activity but not from the API classes.
I have found a method called .runOnUiThread so I tried to implement that.
private void publishProgress(final int i){
logInActivity.runOnUiThread(new Runnable() {
#Override
public void run() {
logInActivity.updateProgress(i);
Log.d("UI THREAD","HIT");
}
});
}
This is what I have come up with, but it doesn't seem to be hitting, I don't even see the Log post.
I did also have an error implementing this but it was resolved when I added Looper.prepare(); to the Log in AsyncTask
AsyncTask
private class RegistrationWeb extends AsyncTask<Void,Void,Void>{
private static final String tag = "API_LogIn";
private String APIKey = null
#Override
protected void onPreExecute() {
super.onPreExecute();
viewFlipper.showNext();
APIKey = getAPIKey();
}
#Override
protected Void doInBackground(Void... voids) {
try{
Looper.prepare();
GetAPIData get = new GetAPIData();
URL url = new URL(API_Register_User+APIKey);
String response = get.GetData(url);
JSONArray jsonArray = new JSONArray(response);
JSONObject jsonObject = jsonArray.getJSONObject(0);
//If the user is accepted
if(jsonObject.getString("_Code").equals("0")){
PublishProgress(8);
PostAPIData post = new PostAPIData();
url = new URL(API_Register_Device);
response = post.PostData(url);
jsonArray = new JSONArray(response);
jsonObject = jsonArray.getJSONObject(0);
} else if(jsonObject.getString("_Code").equals("2")){
}
} catch (MalformedURLException e) {
Log.e(tag,e.toString());
} catch (JSONException e) {
Log.e(tag,e.toString());
} catch (IOException e) {
Log.e(tag,e.toString());
}
return null;
}
private void PublishProgress(final int i){
runOnUiThread(new Runnable() {
#Override
public void run() {
updateProgress(i);
}
});
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
}
You can not directly access string that are present in resource, you will have to to acquire resources first to use its content. You need to call getResources() from your Activity, then you can get the string you are looking for.
YourActivity.context.getResources().getString(R.string.id_name);
Override onProgressUpdate() and then call publishProgress()
public void publishProgress(Integer v) {
Message message = new Message();
message.what = v;
YourActivity.handler.sendMessage(message);
}
#Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
publishProgress(values[0);
}
And change your AsyncTask parameter during its creation from Void to Integer
class RegistrationWeb extends AsyncTask<Integer,Integer,Integer> {
}
In your Activity where your TextView resides on which you want update, make Handler to listen the messages from outer class and in that Handler update your TextView.
Activity:
public static Handler handler = new Handler(){
#Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
//update your text view on the basis of msg.what
}
}
};
Note : Make your TextView loadInfo as static
My program crashs after doInBackground and doesn't come to onPostExecute.
My activity code's related parts are like this:
public static class News {
private String title;
private String content;
private Bitmap image;
public News(String nTitle, String nContent, Bitmap nImage){
title = nTitle;
content = nContent;
image = nImage;
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_news);
final AsyncTask task = new DatabaseConnection(this, Method.GET_ALL_NEWS).execute();
try {
task.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public final void fillListView(List<News> news){
recentNews = news;
if(recentNews != null && !recentNews.isEmpty()){
((ListView)findViewById(R.id.lvNews)).setOnItemClickListener(this);
final int size = recentNews.size();
final String newsTitles[] = new String[size];
for(int i=0; i<size; ++i)
newsTitles[i] = recentNews.get(i).title;
((ListView)findViewById(R.id.lvNews)).setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, newsTitles));
}
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
final News selectedNews = recentNews.get(position);
startActivity(new Intent(this, ANewsActivity.class)
.putExtra("title", selectedNews.title)
.putExtra("content", selectedNews.content)
.putExtra("image", BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher)));
}
My AsyncTask code's related parts are like this:
public DatabaseConnection(Context nContext, Method nMethod){
method = nMethod;
context = nContext;
}
#Override
protected void onPreExecute() {
progressDialog = new ProgressDialog(context);
progressDialog.setMessage(context.getString(R.string.database_connection_wait_message));
progressDialog.setTitle(R.string.database_connection_wait_title);
progressDialog.show();
}
#SuppressWarnings("incomplete-switch")
#Override
protected Void doInBackground(String... params) {
if(method != Method.NONE){
open();
try{
switch(method){
case GET_ALL_NEWS:
final ResultSet rs = conn.createStatement().executeQuery("select baslik, metin, resim from haberler");
news = new ArrayList<News>();
while(rs.next())
news.add(new News(rs.getString(1), rs.getString(2), BitmapFactory.decodeStream(rs.getBlob(3).getBinaryStream())));
break;
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
close();
}
}
return null;
}
#SuppressWarnings("incomplete-switch")
#Override
protected void onPostExecute(Void temp) {
if (progressDialog.isShowing()){
progressDialog.dismiss();
switch(method){
case GET_ALL_NEWS:
((NewsActivity)context).fillListView(news);
break;
}
method = Method.NONE;
}
}
I want UI thread waits until database operations finishes.
By the way there is no initialization problem at variables etc and database returns proper infos and my "news" variable is filled normally.
By the way again I realized it is WORKING on PHONE, STUCKS on EMULATOR interestingly (if I remove wait() method and its try-catch block on main thread code).
It's difficult to say what is crashing without the logcat output, but it would most likely be the main thread of the app because of the .wait() method you are calling in onCreate(). Your onCreate() cannot wait - it must initialize and exit, otherwise you are blocking the main thread of your app and defeating the purpose of the AsyncTask.
I use a worker thread to read text from a url. My thread is as follow. In the first time running, I am sure thread running is finished as I can check sdcard_readstr is null.
In the second time running, when I call thread_download.start();, then the program crashed.
What could be wrong? Thanks
public class DownloadingThread extends AbstractDataDownloading {
#Override
public void doRun() {
// TODO Auto-generated method stub
try {
// Create a URL for the desired page
URL url = new URL(SDcard_DetailView.textfileurl);
// Read all the text returned by the server
BufferedReader in = new BufferedReader(new
InputStreamReader(url.openStream()));
do{
sdcard_readstr = in.readLine();
}while(sdcard_readstr!=null);
in.close();
} catch (MalformedURLException e) {
} catch (IOException e) {
}
}
}
public abstract class AbstractDataDownloading extends Thread{
private final Set<ThreadCompleteListener> listeners
= new CopyOnWriteArraySet<ThreadCompleteListener>();
public final void addListener(final ThreadCompleteListener listener) {
listeners.add(listener);
}
public final void removeListener(final ThreadCompleteListener listener) {
listeners.remove(listener);
}
private final void notifyListeners() {
for (ThreadCompleteListener listener : listeners) {
listener.notifyOfThreadComplete(this);
}
}
#Override
public final void run() {
try {
doRun();
} finally {
notifyListeners();
}
}
public abstract void doRun();
}
EDIT1:
In my thread complete notification, I use runOnUiThreadto use the UI components.
Is that causing problem?
public void notifyOfThreadComplete(Thread thread) {
// TODO Auto-generated method stub
if(downloadingStopbuttonispressed == false){//background process completed
textfileurl = null;
this.runOnUiThread(new Runnable() {
public void run() {
Wifibutton = (Button) findViewById(R.id.Wifiscanning);
Wifibutton.setText("Load another day's data");
final MenuItem refreshItem = optionsMenu.findItem(R.id.airport_menuRefresh);
refreshItem.setActionView(null);
}
});
}
}
I called thread start in onResume() as
#Override
protected void onResume() {
super.onResume();
if(textfileurl != null){
Wifibutton.setText("Stop Data Loading");
buttonStatus = "loading";
setRefreshActionButtonState(true);
thread_download.start();
}
}
EDIT2:
My LogCat image is attached.
My solution is here . I can't reuse the same instance of the Thread object in the second time. I need to create a new instance to call the Thread in the second time. So Thread is suitable for single time running process, for multiple time running process I should use AsyncTask. Even AsyncTack is only for one time execution and for multiple time execution, we should use as new MyAsyncTask().execute(""); I don't understand why people downvote with no reason given. I couldn't find the link in my first search.
In my app I performing loading data from web and then displaying it to user. Before loading data app shows progress dialog. I have problem if user locks phone in the middle of loading operation, or server is overloaded and can't respond in time my application freezes, because it doesn't dismiss progress dialog, or in some cases it crashes because lack on needed data.
If some error happened while loading data I want show some dialog to user to let him know about error and ask him should application repeat last request. I tried to use AlertDialog for it, but I haven't succeed.
Here is code of one activity (There is no progress dialog here, but it demonstrates how I loading data):
#EActivity(R.layout.layout_splash)
#RoboGuice
public class SplashScreenActivity extends Activity {
#Inject
private AvtopoiskParserImpl parser;
#Bean
BrandsAndRegionsHolder brandsAndRegionsHolder;
#ViewById(R.id.splash_progress)
ProgressBar progressBar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
loadData();
}
#Background
protected void loadData() {
publishProgress(10);
LinkedHashMap<String, Integer> brands = null;
try {
brands = parser.getBrands();
} catch (IOException e) {
Log.e(e.getMessage());
}
publishProgress(50);
LinkedHashMap<String, Integer> regions = null;
try {
regions = parser.getRegions();
} catch (IOException e) {
Log.e(e.getMessage());
}
publishProgress(70);
populateData(brands, regions);
}
#UiThread
protected void populateData(LinkedHashMap<String, Integer> brands, LinkedHashMap<String, Integer> regions) {
Intent intent = new Intent(SplashScreenActivity.this, SearchActivity_.class);
brandsAndRegionsHolder.brandsMap = brands;
brandsAndRegionsHolder.regionsMap = regions;
publishProgress(100);
startActivity(intent);
finish();
}
#UiThread
void publishProgress(int progress) {
progressBar.setProgress(progress);
}
}
parser.getBrands() and parser.getRegions() are loading data from the web.
I want to do something like this:
boolean repeatRequest = true;
while (repeatRequest) {
try {
brands = parser.getBrands();
repeatRequest = false;
} catch (IOException e) {
Log.e(e.getMessage());
repeatRequest = showErrorDialog();
}
}
But I didn't manage to do so because this code executes in background thread, but dialog should be shown in UI thread.
I believe that it should be standard approach of doing so, but didn't manage to find it.
Any ides how can I implement this?
The best way is to use AsyncTask.
private class LoadDataTask extends AsyncTask<Void, Integer, Object> {
private ProgressDialog mProgress;
protected Object doInBackground(Void... params) {
// This method runs in background
Object result = null;
try {
result = parser.parse();
} catch (Exception e) {
result = e.getMessage();
}
return result;
}
protected void onProgressUpdate(Integer... progress) {
// This method runs in UI thread
mProgress.setProgress(progress[0]);
}
protected void onPreExecute() {
// This method runs in UI thread
mProgress = new ProgressDialog(context);
mProgress.show();
}
protected void onPostExecute(Object result) {
// This method runs in UI thread
mProgress.dismiss();
if (result instance of String) {
// Here you can launch AlertDialog with error message and proposal to retry
showErrorDialog((String) result);
} else {
populateData(result);
}
}
}
I never got this working in a straightforward manner. Sorry if I'm being a little vague. I'll try to elaborate on what I'm trying to do. I am trying to build a listview that grabs its data from a webservice. Once I initialize a listview, I want to keep polling the webserver periodically and update the contents of the listview. For this I am doing something like this:
public class SampleAutoUpdateList extends Activity {
//Autoupdate handler
private Handler handler = new Handler();
private Runnable updater = new Runnable() {
public void run() {
/*
* Update the list
*/
try {
Log.i("UPDATE", "Handler called");
searchAdapter = getFeed(URL);
searchAdapter.notifyDataSetChanged();
handler.postDelayed(this, Configuration.REFRESH_INTERVAL);
} catch(Exception e) {
Log.e("UPDATE ERROR", e.getMessage());
}
}
};
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.linearmode);
this.context = this;
searchAdapter = getFeed(URL);
LinearLayout l2 = (LinearLayout) findViewById(R.id.secondaryLayout);
ListView list = new ListView(context);
l2.addView(list);
// display UI
UpdateDisplay(list);
updater.run();
}
private SearchAdapter getFeed(String URL) {
try
{
SearchHandler handler = new SearchHandler();
URL url = new URL(URL);
String data = convertStreamToString(url.openStream());
data = data.substring(data.indexOf('['), data.length()-1);
handler.parseJSON(data);
return handler.getFeed();
}
catch (Exception ee)
{
// if we have a problem, simply return null
Log.e("getFeed", ee.getMessage());
return null;
}
}
private void UpdateDisplay(View searchView) {
// TODO Auto-generated method stub
// TODO Auto-generated method stub
searchList = (ListView) searchView;
myProgressDialog = ProgressDialog.show(this,
"Please wait...", "Loading search....", true);
new Thread() {
public void run() {
try{
Thread.sleep(2000);
} catch (Exception e) { }
runOnUiThread(new Runnable() {
#Override
public void run() {
if (searchAdapter == null)
{
Log.e("ERROR", "No Feed Available");
return;
}
searchAdapter.setContext(context);
searchList.setAdapter(searchAdapter);
searchList.setSelection(0);
}
});
// Dismiss the Dialog
myProgressDialog.dismiss();
}
}.start();
}
}
And the SearchHandler class is simple:
public class SearchHandler extends DefaultHandler {
SearchAdapter _adapter;
SearchItem _item;
public SearchHandler()
{
}
public SearchAdapter getFeed()
{
return _adapter;
}
public void parseJSON(String data) {
// TODO Auto-generated method stub
_adapter = new SearchAdapter();
JSONArray parseArray;
try {
parseArray = new JSONArray(data);
for (int i=0; i < parseArray.length(); i++) {
SearchItem item = new SearchItem();
JSONObject jsonUser = parseArray.getJSONObject(i);
item.set_from(jsonUser.getString ("from"));
item.set_msg(jsonUser.getString("msg"));
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
No matter what I do, the handler gets called and the new items are fetched, but the list is never refreshed... Any ideas on what could be going wrong?
Well, it is a little bit difficult to follow your code, since you only have a fragment of it, and few of the really relevant bits. For example, based on your available code, your list should be forever empty, since you never associate the searchAdapter with a ListView...at least in the code you have shown.
That being said, the following lines seem particularly odd:
searchAdapter = getFeed(URL);
searchAdapter.notifyDataSetChanged();
I am going to assume that getFeed() (not shown) creates a new ListAdapter of some sort. If getFeed() is creating a new ListAdapter, there is no need to call notifyDataSetChanged() on it, as its data set hasn't changed -- it's brand new. Moreover, unless you are associating this new ListAdapter to your ListView, the new ListAdapter will have no effect.
If I'm barking up the wrong tree, consider adding lines to your sample showing the implementation of getFeed() and where you are using searchAdapter.