Develop Reference

Android Progress Bar appear and hide

I have a progress bar and I do not want to incorporate a numerical value to show the loading of some content. I just want that the ProgressBar should appear, animate and then go away.
I used:
public void buttonClick(View v){
ProgressBar mProgress=(ProgressBar)findViewById(R.id.my_progress);
mProgress.setVisibility(VISIBLE); //line 1..
//loading data from web... takes time
mProgress.setVisibility(INVISIBLE); //line 2..
}
but when I run this code, both line 1 and line 2 executes, but the UI changes afterwards, which is not desired. I want that when the button is clicked, the progress bar should appear and when the data is downloaded from the web the progress bar should disappear.
I tried setting the visibility from another thread, but it didn't work as UI changes are not allowed in other threads.

You download your data in AsyncTask right? Put this code
private class DownloadData extends AsyncTask<Void, Void, Void>{
#Override
protected void onPreExecute() {
super.onPreExecute();
mProgress.setVisibility(View.VISIBLE);
}
#Override
protected Void doInBackground(Void... params) {
// download your data here
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
mProgress.setVisibility(View.GONE);
}
}

The best way implement it by using an AsyncTask
MyTask.java
class MyTask extends AsyncTask<Void, Void, Void> {
ProgressDialog dialog;
Context context;
MyTask(Context context){
this.context=context;
}
#Override
protected void onPreExecute() {
dialog=new ProgressDialog(context);
dialog.setMessage("Please wait...");
dialog.setIndeterminate(true);
dialog.setCancelable(false);
dialog.show();
}
#Override
protected Void doInBackground(Void... params) {
//do your task here
}
#Override
protected void onPostExecute(Void result) {
if(dialog.isShowing()){
dialog.dismiss();
}
}
}
You can start the task like this:
public void buttonClick(View v){
new MyTask(YourActivity.this).execute();
}
You can modify the AsyncTask accordingly to retrieve the result.
Hope it helps. :)

ProgressDialog show too much late with Asynch task in Android

I am new in android. I am trying to display ProgressDialog when click on button .
This is my code:
// set listener
btn_Login.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//progress.show();
MyAsynch asynch = new MyAsynch();
asynch.execute();
}
In this code progress dialog too much late appear when i am comment on Asynctask object then progress dialog appear normally.
I am puting my progress dialog in
AsynchTask method
onPreExecute() but same out put dialog display late .
How to solve my problem..??
I am also read stack answers following link but not solve my problem .
async task progress dialog show too late
ProgressDialog appears too late and dissapears too fast
here is my Asynctask code
private class MyAsynch extends AsyncTask<String, Void, String> {
ProgressDialog progress;
String login_stat;
String stat;
#Override
protected void onPreExecute() {
progress = new ProgressDialog(this);
progress.setTitle(" User Login ");
progress.setMessage("Please Wait!!");
progress.setCancelable(false);
progress.setIndeterminate(true);
progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progress.show();
}
#Override
protected String doInBackground(String... urls) {
try {
login_stat = s_ApiHandling.doLogin(m_Et_Username.getText()
.toString().trim(), m_Et_Password.getText()
.toString().trim());
} catch (Exception e) {
System.out.println("internet connection loss ");
stat = "ERORR";
e.printStackTrace();
}
return stat;
}
#Override
protected void onPostExecute(String status) {
progress.dismiss();
}
}

You are probably doing too much in onPreExecute

Remove progress.cancel() from your doInBackground method and put it in to a onPostExecute method in your AsyncTask (like the second link you posted)
You shouldn't have anything talking to the UI in a background thread - that should all be done in pre/post execution.

you code should look like this:
AsyncTask<String, Void, String>()
{
private ProgressDialog progressDialog = ProgressDialog.show(this, "", "Loading...");
#Override
protected void onPostExecute(String result)
{
progressDialog.dismiss();
}
#Override
protected String[] doInBackground(String... params)
{
//ALL CODE GOES HERE.
}
}
When you call the asynctask you must not use the get() method or the progress dialog won't work correctly.

ProgressDialog not shown in AsyncTask

I have a huge database (40MB) on an SDCard. I need fetch data, with LIKE in query, which is very slow.
DB request takes about 5 seconds. Therefore, I need to do it asynchronously and with ProgressDialog.
I tried it with AsyncTask, but problem is with ProgressDialog. It was implemented this way:
private class GetDataFromLangDB extends AsyncTask<String, String, String> {
private final ProgressDialog dialog = new ProgressDialog(TranslAndActivity.this);
#Override
protected void onPreExecute() {
super.onPreExecute();
urDBCursor.close();
curDBCursor = null;
scaAdapter = null;
this.dialog.setMessage("Loading data...");
this.dialog.show();
}
#Override
protected String doInBackground(String... whatSearch) {
String result = "";
if (myDatabaseAdapter != null) {
curDBCursor = myDatabaseAdapter.fetchAll(whatSearch[0]);
}
return result;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
prepareListView();
}
}
The problem is that ProgressDialog is not shown during the DB request.
After finished database query, it flash on screen for a short time. When user tries
to tap on screen during database request, UI is freezed, and after DB request
message about 'not responding' is shown.
I tried it with a thread this way:
public void startProgress(View view, final String aWhatSearch) {
final ProgressDialog dialog = new ProgressDialog(MyActivity.this);
if (curDBCursor != null){
curDBCursor.close();
curDBCursor = null;
}
dialog.setMessage("Loading data...");
dialog.show();
Runnable runnable = new Runnable() {
public void run() {
curDBCursor = myDatabaseAdapter.fetchAll(aWhatSearch);
// dirty trick
try {
Thread.sleep(250); // it must be here to show progress
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.post(new Runnable() {
public void run() {
if (dialog.isShowing()) {
dialog.dismiss();
}
prepareListView();
}
});
}
};
new Thread(runnable).start();
}
The result was the same, but when I used the trick with Thread.sleep(250);
ProgressDialog was shown during the database request. But it is not spinning,
it looks freezed during the DB request.
DB stuff is called this way (after tap on search button):
btnSearchAll.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// AsyncTask
new GetDataFromLangDB().execute(edtTextToSearch.getText().toString());
// or Thread
//startProgress(null, edtTextToSearch.getText().toString());
}
});
I found a lot of problems like this in SO, but nothing was useful for me.
Could it be that DB is on SD Card?

I put the definition of the dialog into the AsyncTask Class and it works fine for me.
Take a look at this exampel (You have to change NAMEOFCLASS in the name of your CLASS:
private class doInBackground extends AsyncTask<Integer, Integer, Void> {
final ProgressDialog dialog = new ProgressDialog(NAMEOFCLASS.this) {
#Override
protected void onPreExecute() {
dialog.setCancelable(false);
dialog.setTitle(getString(R.string.daten_wait_titel));
dialog.setIcon(R.drawable.icon);
dialog.setMessage(getString(R.string.dse_dialog_speichern));
dialog.show();
}
#Override
protected void onCancelled() {
dialog.cancel();
}
....
#Override
protected void onProgressUpdate(Integer... values) {
// DO YOUR UPDATE HERE
}
#Override
protected void onPostExecute(Void result) {
dialog.dismiss();
}
}

Maybe this SO answer could help you. It looks like similar problem. Try to use AsyncQueryHandler for querying your database

declare you Dialog box on Class (Activity) level like this
private ProgressDialog dialog = null;
show the progress dialog and call the AsyncTask class when you want to start you Busy work..like onButton click or any
dialog = ProgressDialog.show(this,"Sending Email to your account please! wait...", true);
SendingEmailTask task = new SendingEmailTask();
String s = "";
task.execute(s);
create your inner class like
private class SendingEmailTask extends AsyncTask<String, Void, String> {
protected String doInBackground(String... urls) {
//do your work here..
// like fetching the Data from DB or any
return null;
}
#Override
protected void onPostExecute(String str) {
//hide progress dialog here
dialog.dismiss();
}
}
let me know if this help!!

Activity not starting

I can get the progress dialog to stop, but the TabbedView activity never starts, just goes to a black screen. Any ideas?
class DownloadWebPageTask extends AsyncTask<String, Void, String> {
private final ProgressDialog dialog = new ProgressDialog(MainScreen.this);
#Override
protected void onPreExecute() {
dialog.setMessage("Gathering data for\n"+selectedSportName+".\nPlease wait...");
dialog.show();
}
#Override
protected String doInBackground(String... urls) {
String response = "";
updateMaps();
return response;
}
#Override
protected void onPostExecute(String result) {
dialog.dismiss();
startTabbedViewActivity();
}
}
private void startTabbedViewActivity(){
Intent intent = new Intent(this, TabbedView.class);
intent.putExtra(SPORT_NAME_EXTRA, selectedSportName);
intent.putExtra(HEADLINES_FOR_SPORT_EXTRA, existingSportHeadlines.get(selectedSportName));
intent.putExtra(SCORES_FOR_SPORT_EXTRA, existingSportScores.get(selectedSportName));
intent.putExtra(SCHEDULE_FOR_SPORT_EXTRA, existingSportSchedule.get(selectedSportName));
startActivity(intent);
}
I have looked over the Manifest file, and I'm not seeing anything weird looking. Can't figure this one out.

Is the layout of the activity orientated correctly
android:orientation="vertical"

You forgot to add #Override above 'onPostExecute' method so it is not executed at all.

ProgressDialog wont show onPreExecute in my asynctask?

Ive looked at some questions and non answer the problem im having..
I have this asyncTask...
private class LoadData extends AsyncTask<Void, Void, Void>{
protected Void onPreExecute(Void...arg0){
super.onPreExecute();
ProgressDialog dialog = ProgressDialog.show(shoppingClass.this, "",
"Loading. Please wait...", true);
dialog.show();
return null;
}
#Override
protected Void doInBackground(Void... params) {
item = we.getText().toString();
getUserPreference();
itemLookup.loadUrl(url);
return null;
}
#Override
protected void onPostExecute(Void notused){
itemLookup.setVisibility(View.VISIBLE);
}
}
The problem is the progessDialog is not showing up? I dont know why...Im doing everything write according to the documentation.

You are not overriding correctly the method. Change onPreExecute to this:
#Override
protected void onPreExecute() {
super.onPreExecute();
ProgressDialog dialog = ProgressDialog.show(shoppingClass.this, "",
"Loading. Please wait...", true);
dialog.show();
}

it could just be that doinbackground is completing too quickly for you to be able to see the dialog.

Check that shoppingClass.this has the UI context. Also, you shouldn't have to call .show() twice on it and you don't have to return null as its void (lowercase).