A lesson that took me an hour to figure out: android progress dialogues will only be displayed on the UI if called/shown in a thread or async task. Basically when try to call a progress dialog directly from a fragment, android would simply not show the dialog.
So the code would look something like this:
| uploadButton.setOnClickListener(new Button.OnClickListener() { | |
| public void onClick(View v) | |
| { | |
| final ProgressDialog progressDialog = new ProgressDialog(getActivity()); | |
| //perform upload action | |
| Thread thread = new Thread() | |
| { | |
| @Override | |
| public void run() { | |
| getActivity().runOnUiThread(new Runnable() { | |
| @Override | |
| public void run() { | |
| progressDialog.setTitle("File Upload"); | |
| progressDialog.setMessage("Please Wait…"); | |
| progressDialog.isIndeterminate(); | |
| progressDialog.show(); | |
| } | |
| }); | |
| uploadFile(); | |
| getActivity().runOnUiThread(new Runnable() { | |
| @Override | |
| public void run() { | |
| progressDialog.dismiss(); | |
| } | |
| }); | |
| } | |
| }; | |
| thread.start(); | |
| } | |
| }); |
The code shows how to attach a listener that will trigger a sequence of events when a button (uploadButton) is clicked. The sequence is:
- Initialize the progessDialog (so we can refer to the variable across threads)
- Start a new thread
- Within the thread, prepare the look and feel of the progress dialog and display it in the UI thread
- Do your long task (uploadFile)
- Dismiss the progress dialog in the UI thread
