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:
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| 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
David Vassallo's Blog 