Sometimes, you may want to update the text shown in the progress dialog. If you try to perform this in doInBackground() you’ll get an exception along the lines: Only the original thread that created a view hierarchy can touch its views The solution is to not do it in doInBackground() but instead trigger onProgressUpdate() and […]
Tag: progress
ProgressDialog in AsyncTask: Dynamic Update max()
Sometimes you determine the max of the progress bar in the background task. Unfortunately, there’s almost no way to transmit that to an UI thread-executed method like onProgressUpdate() (well, you could, but that’d be abusing the method). Instead you can do something like:
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public class MyTask extends AsyncTask<Params, Progress, Result> { private ProgressDialog progressDialog; int max; int offset; @Override protected Void doInBackground(Params... params) { this.max = calculate_max(); this.offset = 0; for (int i=0; i<this.max; i++) { // ... publishProgress(new Progress()); // ... } return null; } @Override protected void onProgressUpdate(Result... values) { super.onProgressUpdate(values); this.progressDialog.setMessage(values[0].label); this.progressDialog.setProgress( calculateProgressPercent(this.offset, this.max) ); this.offset ++; } private int calculateProgressPercent(int done, int max) { done = done * 100; return done / max; } } |
This way, the variables are updated in their own thread and […]
ProgressDialog and AsyncTask: Table of Contents
Here are some things I’ve learned on using a ProgressDialog in an AsyncTask. Dynamic Update Text/Title Dynamic Update max() A little experiment: If you find this post and ad below useful, please check the ad out :-)