Question

Working with Android I’ve got an error while I try to show a progressbar in an asynctask. I have the error at the bold line. The variable context is the context of the app, I’m sure. Here there’s the code:

public class UpdateDBTask extends AsyncTask {

ProgressDialog progressDialogListFiles;
ProgressDialog progressDialogUpdateDB;

protected void onPreExecute () {
    progressDialogUpdateDB = new ProgressDialog(context);
    progressDialogUpdateDB.setIndeterminate(false);
    progressDialogUpdateDB.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
    progressDialogUpdateDB.setMessage("Analyzing files...");
    progressDialogUpdateDB.setCancelable(false);
    progressDialogUpdateDB.setProgress(0);

    progressDialogListFiles = new ProgressDialog(context);
    progressDialogListFiles.setIndeterminate(true);
    progressDialogListFiles.setMessage("Listing files...");
    progressDialogUpdateDB.setCancelable(false);
}

protected Boolean doInBackground(String... paths) { 
    updateDB(paths);
    return true;
}

protected void updateDB(String[] paths) {

    /*.....*/
        **progressDialogListFiles.show();**
    /*...*/
}

}

Can you help me? Thanks!

Answer 1

You are attempting to update the UI from a non-UI thread, namely the thread being used to process doInBackground(). Please update your UI from onPreExecute(), onProgressUpdate(), or onPostExecute().