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Android ListView within fragment doesn't refresh without a button click

My ListView doesn't refresh its contents when I call the appropriate method unless the method was invoked with a button click.
The follow example code is how my test button works (temporary button to check to see if it was a problem with my refresh code):
testBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
exampleRefresh();
}
});
And the method it calls:
public void exampleRefresh() {
exampleAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, arrayOfItems());
exampleListView.setAdapter(exampleAdapter);
}
This works fine.
However, if I call exampleRefresh() in the switch statement for a context menu, nothing happens. Again, when I click the test button, the ListView refreshes instantly. These are calling the same method, I don't understand the issue.
I have tried adding nofifyDataSetChange(), but it doesn't work. The ListView only refreshes when I invoke a button press.
It's also worth noting that even if I call the method on the invoke of a context menu, it refreshes. It does not do anything without an invoke, it appears.
Any help will be very much appreciated.

have you tried to
exampleAdapter = new ArrayAdapter<String>();
exampleAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, arrayOfItems());
exampleListView.setAdapter(exampleAdapter);
this should force it to clear and re-add the

if you are changing data in list and then you want to refresh listview then dont call setadapter method again. just call below method:
exampleAdapter.notifyDataSetChange();

Try invoking notifyDataSetChange() from exampleListView.post() like this:
exampleListView.post(new Runnable() {
public void run() {
exampleAdapter.notifyDatasetChange();
}
}

Android Trying to display a welcome fragment when app starts, but not after

I've been looking for a way to have the blank detail side of my fragment layout host a welcome screen (or something - login perhaps) on start up. Afterwards, when a user presses one of the left side menu items, I'd like to eliminate the fragment for the remainder of the program run. I don't want to add it to the backstack, as that messes up my configuration changes. I've considered using shared prefs to host a boolean about whether the fragment has been displayed. The only concern with this method is where to safely reset the boolean value for the next run of the app. I'm of the impression that there's no gaurantee that the onStop, onDetach etc. will definitely get called upon closing of the app, so if the app got closed in the wrong state, it would be rendered useless ( the first fragment wouldn't display - crash )
Anyone have any ideas on how I could implement a filler for the right side of the app upon startup?
I've been trying to add something to the onCreate of my main activity thus far with no success.
Thanks in advance.
Ken

If your fragment can be part of its own Activity, you can use the android:noHistory="true" attribute to keep the Activity off of the backstack. If your user tries to navigate backwards, it'll hit the bottom of the backstack twice before exiting your application.
If you can't split your fragment into its own activity, noHistory may not work -- I can't say as I haven't tried it myself.

I was able to come up with a solution to creating a welcome or login screen which will display both fragments and activities from the main activity. Seems to be working fine as tested.
private boolean welcomeShown;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_list);
if (findViewById(R.id.item_detail_container) != null) {
mTwoPane = true;
((MainFragment) getSupportFragmentManager().findFragmentById(
R.id.item_list)).setActivateOnItemClick(true);
}
if (savedInstanceState != null){
welcomeShown = savedInstanceState.getBoolean("displayed");
}
if(!welcomeShown){
if (mTwoPane){
WelcomeFragment welcomeFragment = new WelcomeFragment();
getSupportFragmentManager().beginTransaction()
.add(R.id.item_detail_container, welcomeFragment)
.commit();
}
else{
Intent welcomeIntent = new Intent(this, WelcomeActivity.class);
startActivity(welcomeIntent);
welcomeShown = true;
}
}
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putBoolean("displayed", true);
}

Custom AlertDialog fails to initialize in onCreate()

I'm trying to build a custom AlertDialog by extending the AlertDialog class.
As usual, I'm setting up the dialog inside its onCreate() method. Or, I'm trying to do so:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setTitle("Some title");
this.setButton(BUTTON_POSITIVE, "Click me", (DialogInterface.OnClickListener)null);
final FrameLayout custom = (FrameLayout) this
.findViewById(android.R.id.custom);
custom.addView(this.getLayoutInflater().inflate(R.layout.mydlg, null),
LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
}
Now, when it comes to displaying an instance of this dialog, nothing is shown. The current Activity fades out and loses focus but not a single pixel of my dialog is displayed. Pressing Back brings the Activity back to the foreground, indicating to me that a dialog actually is shown, but just a completely empty one.
However, when I create an AlertDialog and use, for instance, dlg.setButton(BUTTON_POSITIVE, "Click me", (DialogInterface.OnClickListener)null);
the dialog is shown with the respective button.
Even when I set up my custom dialog in its constructor using the very same code as above everything seems to work ok.
Now, how can this be? Why can't I seem to initialize my dialog in its onCreate() method? Isn't this the way you're supposed to initialize any GUI element? What am I missing?
EDIT
Please note, that something is 'shown', fading out the Activity and taking focus from it. It's just that it seems to be completely empty/invisible.
Here another attempt:
this.setTitle("Some title");
this.setButton(BUTTON_POSITIVE, "Click me", (DialogInterface.OnClickListener)null);
final View v = this.getLayoutInflater().inflate(R.layout.mydlg, null);
this.setView(v);
These exact lines do work when put into my dialog's constructor.
These exact lines do not work when put into my dialog's onCreate().
What is going on here?!
Generally, am I not supposed to do it in onCreate()? - Am I facing trouble if I resort to doing the above initialization in the constructor instead? (This does not seem too clean to me, anyway.)

You need to call the show() method in order to see something.

You should consider using AlertDialog.Builder instead of subclassing AlertDialog itself. It allows you to do all the things you need in your example (in order: setTitle(),setPositiveButton() and setView() ). Don't forget to call create() at the end to actually get your dialog.
Also, check if your onCreateDialog() and onPrepareDialog() activity methods are implemented correctly. If you don't have them implemented at all (an unmanaged dialog), consider doing that anyway, especially if your app allows for orientation changes. You probably know about this, but here is a tutorial:
http://developer.android.com/guide/topics/ui/dialogs.html
also, DialogFragments are a bit easier way to implement this, but you need a newer API version or the Compatibility package:
http://developer.android.com/reference/android/app/DialogFragment.
One final issue - where are you calling show() in your activity? onResume() should be OK, onCreate() not as much.

Sorry I'm late to the party :)
You have to thing differently for the alert dialog.
The way I did it is to customize the view before creating the alert dialog:
// This is the activity that is the background of the AlertDialog
public class Main extends Activity {
public static final int DIALOG_CONFIG = 1;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.emptybackground);
}
#Override
protected void onStart() {
super.onStart();
// Open the alert dialog on openning the Activity
showDialog(Main.DIALOG_CONFIG );
}
protected Dialog onCreateDialog(int id) {
LayoutInflater factory = LayoutInflater.from(this);
switch (id) {
case DIALOG_CONFIG:
// Here, we load the existing view R.layout.config
configView = factory.inflate(R.layout.config, null);
configDialog = new AlertDialog.Builder(this)
.setTitle("Configuration")
.setView(configView)
.create();
// Using configView, you can do whatever you want with the view. Here, we add value to a spinner.
Spinner spinner = (Spinner)configView.findViewById(R.id.config_select_conn);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
adapter.add("TCP");
adapter.add("Bluetooth");
spinner.setAdapter(adapter);
return configPrinter;
}
return null;
}
}

you should call custom_alertDialog.create(); before custom_alertDialog.show();

OnResume() not called by Pressing back Button in ActivityGroup

As ActivityGroup manages the Activities in the form of view, so when I try to return back to the Parent Activity that called the child Activity in ActivityGroup the onResume() is not being called.
I tried calling the OnResume() like this.
((Activity)view.getContext()).onResume();
But its not working, instead finish() is working is fine for me.
((Activity)view.getContext()).finish();
So, I am able to get the Activity from the View, but not able to call the onResume(), any idea will be appreciable.

Try this, when you press back button using ActivityGroup.
public void back()
{
if ( arrList.size() > 1 )
{
arrList.remove(arrList.size() - 1);
View v = arrList.get(arrList.size() - 1);
Activity_name object = ((Activity_name)v.getContext());
object.onResume();
setContentView(v);
}
else {
this.finish();
}
}

onResume is a lifecycle method called by OS when activity comes to the top of the stack. You can't call it directly.

Update View at runtime in Android

The example is pretty straightforward: i want to let the user know about what the app is doing by just showing a text (canvas.drawText()). Then, my first message appears, but not the other ones. I mean, i have a "setText" method but it doesn't updates.
onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(splash); // splash is the view class
loadResources();
splash.setText("this");
boundWebService();
splash.setText("that"):
etc();
splash.setText("so on");
}
The view's text drawing works by doing just a drawText in onDraw();, so setText changes the text but doesn't show it.
Someone recommended me replacing the view with a SurfaceView, but it would be alot of trouble for just a couple of updates, SO... how the heck can i update the view dinamically at runtime?
It should be quite simple, just showing a text for say 2 seconds and then the main thread doing his stuff and then updating the text...
Thanks!
Update:
I tried implementing handler.onPost(), but is the same story all over again. Let me put you the code:
public class ThreadViewTestActivity extends Activity {
Thread t;
Splash splash;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
splash = new Splash(this);
t = new Thread(splash);
t.start();
splash.setTextow("OA");
try { Thread.sleep(4000); } catch (InterruptedException e) { }
splash.setTextow("LALA");
}
}
And:
public class Splash implements Runnable {
Activity activity;
final Handler myHandler = new Handler();
public Splash(Activity activity) {
this.activity=activity;
}
#Override
public void run() {
// TODO Auto-generated method stub
}
public synchronized void setTextow(final String textow) {
// Wrap DownloadTask into another Runnable to track the statistics
myHandler.post(new Runnable() {
#Override
public void run() {
TextView t = (TextView)activity.findViewById(R.id.testo);
t.setText(textow);
t.invalidate();
}
});
}
}
Although splash is in other thread, i put a sleep on the main thread, i use the handler to manage UI and everything, it doesn't changes a thing, it only shows the last update.

I haven't hit this yet, but I think the usual pattern is to do lengthy initialization in a background thread, and use Handler.post() to update the UI. See http://developer.android.com/reference/android/widget/ProgressBar.html for a different, but possibly related, example.
Also see this answer, especially the first paragraph:
The problem is most likely that you
are running the splash screen (some
sort of Dialog such as ProgressDialog
I assume) in the same thread as all
the work being done. This will keep
the view of the splash screen from
being updated, which can keep it from
even getting displayed to the screen.
You need to display the splash screen,
kick off an instance of AsyncTask to
go download all your data, then hide
the splash screen once the task is
complete.
Update (based on your update and your comment): You are not supposed to update the UI in any thread except the one where your Activity is created. Why is it impossible for you to load your resources in a background thread?

First: onCreate is executed on main UI thread of application so no UI updates until you leave it. Basically you need one thread to execute long running tasks and some mechanism to push updates into the UI.
Most usual approach is to extend AsyncTask see this link for further info

i suppose that your view is an extended view and you call onDraw for drawing the view, so, maybe the view isn´t 'refresh' their state, so try this
onCreate(Bundle bundle) {
setContentView(splash); // splash is the view class
loadResources();
splash.setText("this");
splash.invalidate();
boundWebService();
splash.setText("that"):
splash.invalidate();
etc();
splash.setText("so on");
splash.invalidate();
}