how to show progress dialog in oncreate in android app - android

In onCreate() of the activity, I'm force changing the orientation of the activity from portrait to landscape. This is working but there is a small delay of about a sec in the emulator. This activity is actually one of the tabs. So when the user clicks on the tab he would expect an immediate response. So I want to show a progress dialog until the view is completely loaded. How do I achieve this? I tried to do the below but it doesn't work,
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.chart);
ProgressDialog dialog = new ProgressDialog(this);
dialog.setMessage("Loading...");
dialog.show();
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
.
.
.
dialog.dismiss();//after the view is loaded completely }
Any suggestion is appreciated.

Actually, I don't think your application is visiable yet .. not at the onCreate(). Check the eventing lifecycle ... onResume or maybe onStart ... where ever your Acitivity is actually visiable is where you should do this.

Related

ImageView in SplashScreen is not showing

I am very new to android and trying to add a splash screen I am half way succeeded. But a weird think happening that surely an easy one. here i have tried :-
I wanted to stop the SplashScreen for some time. This splash screen layout contain a ImageView that show the appLogo.
public class SplashActivity : Activity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.SplashScreen);
ImageView splashScreenImage = FindViewById<ImageView>(Resource.Id.appLogo);
splashScreenImage.SetImageResource(Resource.Drawable.splLogo);
Thread.Sleep(30000);
StartActivity(typeof(MainActivity));
}
}
Actualy my splash screen waiting stopping for some time but ImageView is not showing it come out at the last moment when new activity is going to start.
Why is this happening ? any help is appreciated :)
problem:
Thread.Sleep(30000);
It is not showing because you are blocking your UI thread to process the SetContentView to display in the screen thus it is not showing.
What it is really doing is that it will wait for 30 second without the display/black screen and change activity.
Solution:
Use a timer or Handler instead of sleeping the thread.

Android DialogFragment progress bar

I've searched everywhere and I can't find a solution to this problem.
Basically I have a login screen and I'm trying to get a progress spinner to show up while it's logging in to the server (via a thread), and then dismiss it after the login is successful. It has to work while changing orientations.
I am using DialogFragment with the Android compatibility package to make a progress bar (can't find any documentation on it, only for basic\alert dialog) because showDialog() is deprecated now. Right now I just show a custom message box as a login spinner.
In Summary:
How can I set up a Progress spinner with DialogFragment.
How can I dismiss it in another thread after orientation changes.
For showing a progress spinner, just override DialogFragment.onCreateDialog() in your dialog fragment like this (no need for overriding onCreateView()):
#Override
public Dialog onCreateDialog(final Bundle savedInstanceState) {
final ProgressDialog dialog = new ProgressDialog(getActivity());
//
dialog.setTitle(R.string.login_title);
dialog.setMessage(getString(R.string.login_message));
dialog.setIndeterminate(true);
dialog.setCancelable(false);
// etc...
return dialog;
}
As for dismissing that dialog fragment from somewhere else, you'll need to get a hold of FragmentManager (from inside your next FragmentActivity or Fragment) and call popBackStack() on it (if you don't do any other fragment transaction in the meantime).
If there's more steps/fragment transactions between your progress dialog fragment and the next activity, you'll probably need one of the other popBackStack(...) methods that take an ID or tag to pop everything up to your progress dialog fragment off the stack.
I know this is old question but I want to share much better solution for this
According to Android Development Protip:
"Stop using ProgressDialog,Inline indicators are your friend"
As Roman Nurik states:
This one's quick. Stop using ProgressDialog and other modal loading
indicators. They're extremely interruptive and annoying, especially
when:
You see one every time you switch tabs.
You can't Back out of them.
They say "Please wait." No thanks, I'd rather just uninstall.
Either show loading indicators inline with your content (e.g.
http://developer.android.com/training/animation/crossfade.html) or better yet, load small amounts of data in the
background so that you minimize the need to even show a loading
indicator.
More about progress & activity in the design guidelines.

Homing Out of Activity Causes Dialog Boxes Not To Appear When Restarted

I've been poking around at this problem and I can't seem to figure it out. I have a simple app with a few normal views and a GL surface view, I make a few dialog boxes using onCreateDialog() and everything seems fine.
#Override
protected Dialog onCreateDialog(int id)
{
super.onCreateDialog(id);
Dialog m_Dialog = null;
// help dialog
if (id == HELP_DIALOG)
{
m_Dialog = new Dialog(this);
m_Dialog.setContentView(R.layout.help_dialog);
m_Dialog.setTitle("Instructions - Press BACK to close");
}
}
However if I use home to exit the app then go back into the app the dialogs no longer appear, however the screen dims as if the dialog was being displayed. I am getting the call to onPrepareDialog() even when the dialog does not show, I tried some things in there like calling show() off of the dialog. It gets a bit more strange, if I then switch to my GL surface view and back the dialogs work again. I am using a ViewAnimator to switch between my views. I am pretty sure I am handling the lifecycle correctly, over riding onPause() / onResume()
#Override
protected void onResume()
{
super.onResume();
m_Sensors.StartSensors();
m_GameThread.Pause(false);
glSurface.onResume();
}
As always, thanks for the help.
I haven't tried working with GL on android, but I have experienced some home button/re-open app weirdness myself recently - in my case it turned out to be connected to the issues below, which you might want to check out:
http://code.google.com/p/android/issues/detail?id=5277
http://code.google.com/p/android/issues/detail?id=2373
Hope it can help you get on the right track.

How to save a Progress Dialog state correctly?

In my app when i do some long work i'm using a Progress Dialog while the work isn't finished.
I'm looking for it in every place but without sucess. Everything that i founded is all about saving user interface elements states.
Then, i would like to know how i can save progress dialog state correctly ?
I want this working because when the orientation screen change the app crashes.
Shoul i use onSaveInstanceState() method ? How ? I try using saving as a bundle but without succes...
Any advice would be nice...
thanks
I think, your dialog crashes on orientation change because you are not using
#Override
protected Dialog onCreateDialog(int dialogID, Bundle args)
and
showDialog(dialogID);
to show your dialog.
I had the same problem with an alert dialog. As I see it, if you don't create dialog that way, it becomes linked to your activity, and when activity is dead, the system finds that a dialog still try to access that dead activity, not new one.
You need to add this to the manifest file for the activity in which you are showing the dialog:
android:configChanges="keyboardHidden|orientation"
to handle the screen orientation you must use onRetainNonConfigurationInstance()
you can find a more extensive explanation about screen orientation here: Faster Screen Orientation.
The way I do this in my applications is overriding the onConfigurationChanged() method in the Activity like so:
#Override
public void onConfigurationChanged(Configuration config) {
//Just switch the layout without respawning the activity
super.onConfigurationChanged(config);
}
This hasn't given me any issues as of yet and my Activity doesn't reload or restart when the orientation is changed.

Dismiss dialog after screen orientation change

1) I launch a background task (via AsyncTask)
new FindJourneyTask().execute(); // FindJourneyTask extends AsyncTask
2) Still in the main thread (just before new thread is launched) I create a dialog with showDialog(dialogId)
// this method is in FindJourneyTask
protected void onPreExecute() {
showDialog(DIALOG_FINDING_JOURNEY);
}
3) Screen orientation changes and the Activity is recreated
4) How can I now dismiss the dialog from the FindJourneyTask? Calling dismissDialog(dialogId) does nothing.
// this method is in FindJourneyTask
protected void onPostExecute(FindJourneyResult result) {
dismissDialog(DIALOG_FINDING_JOURNEY); // does nothing
}
This is a common problem, and there are no real good solutions. The issue is that on screen orientation change, the entire Activity is destroyed and recreated. At the same time, the Dialog you previously had is re-created in the new Activity, but the old background task still refers to the old Activity when it tries to dismiss the dialog. The result is that it dismisses a dialog which was long ago destroyed, rather than dismissing the dialog the new orientation created.
There are three basic solutions:
Override the default orientation-handling code so that your Activity is not destroyed upon rotation. This is probably the least satisfactory answer, as it blocks a lot of code that is automatically run upon orientation changes.
Create a static member variable of your Activity that references the Activity itself, so you can call STATIC_ACTIVITY_VARIABLE.dismissDialog().
Code a solution in which the background task keeps track of the current Activity and updates itself as necessary.
These three solutions are discussed at length here: http://groups.google.com/group/android-developers/browse_thread/thread/bf046b95cf38832d/
There is a better solution to this problem now which involves using fragments.
If you create a dialog using DialogFragment, then this fragment will be responsible for maintaining your dialog's lifecycle. When you show a dialog, you supply a tag for your fragment (DialogFragment.show()). When you need to access your dialog, you just look for the necessary DialogFragment using FragmentManager.findFragmentByTag instead of having a reference to the dialog itself.
This way if device changes orientation, you will get a new fragment instead of the old one, and everything will work.
Here's some code based also in #peresisUser answer:
public void onSaveInstanceState(Bundle outState) {
AppCompatActivity activity = (AppCompatActivity) context;
FragmentManager fragmentManager = activity.getSupportFragmentManager();
DialogFragment dialogFragment = (DialogFragment) fragmentManager.findFragmentByTag("your_dialog_tag");
if(dialogFragment!=null) {
Dialog dialog = dialogFragment.getDialog();
if(dialog!=null && dialog.isShowing()) {
dialogFragment.dismiss();
}
}
}
This is long after the question was asked and answered, but i stumbled upon this problem also and wanted to share my solution...
I check in onSavedInstance() which runs on orientation change, whether the dialog is showing or not with dialog.isShowing(), and pass it into outState variable. Then in your onCreate(), you check this var if it's true. If it is, you simply dismiss your dialog with dialog.dismiss()
Hope this helps others :()
I tried adding setRetainInstance(true); on OnCreate function of DialogFragment. This will cause dialog to dismiss on rotation.
Just add this line to specific activity in your Manifest to solve this problem android:configChanges="orientation|screenSize|smallestScreenSize"
like this,
<activity
android:name=".PDFTools"
android:exported="false"
android:configChanges="orientation|screenSize|smallestScreenSize"
android:theme="#style/Theme.DocScanner.NoActionBar" />

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