CODEWITHSUNDEEP
androidandroid-asynctaskprogressdialog
MM Manuel
MM Manuel

Reputation: 385

ProgressDialog does not appear in method onProgressUpdate

In an Asyntask, i instantiate a progress Dialog in global variables of Asyntask:

ProgressDialog progressDialog;

Then, in DoInBackGround, i call "publishProgress", so onProgressUpdate in called. There, in onProgressUpdate, i have the following code:

this.progressDialog=new ProgressDialog(mActivity);
                this.progressDialog.setCancelable(true);
                this.progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                this.progressDialog.setTitle("Iniciando la comunicación");
                this.progressDialog.show();

I don´t know why, the progressDialog is never shown. I have tried using Toast with the same context, and it works fine. Although progressDialog not.

---------UPDATE--------------

Finally, I've figure it out using notifications.

Upvotes: 1

Views: 452

Answers (3)

Linh
Linh

Reputation: 60913

Organize your AsyncTask like this

private class YourTask extends AsyncTask<String, String, String> {
    ProgressDialog progressDialog;
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        ...
        // show the dialog
        this.progressDialog=new ProgressDialog(mActivity);
            this.progressDialog.setCancelable(true);
            this.progressDialog.setProgressStyle(ProgressDialog. STYLE_HORIZONTAL);
           //this.progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
            this.progressDialog.setTitle("Iniciando la comunicación");
            this.progressDialog.show();
    }

    @Override
    protected String doInBackground(String... urls) {

        ...
        publishProgress("" + progress);
        ...
    }

    protected void onProgressUpdate(String... progress) {        
      progressDialog.setProgress(Integer.parseInt(progress[0]));
    }

    @Override
    protected void onPostExecute(String result) {
        // dismiss the dialog           
        progressDialog.dismiss();
        ...
    }
}

Also you want to public the progress when the AsyncTask is running, so you need a STYLE_HORIZONTAL ProgressBar not STYLE_SPINNER ProgressBar

Hope this help

Upvotes: 4

Vyacheslav
Vyacheslav

Reputation: 27211

I saw this problem two years ago. There is something unpredictable behaviour while main UI thread interaction. The solution I found is to use Thread instead of AsyncTack.

A quick simple example:

new Thread(new Runnable() {
                    public void run() {

//background code to calculate
//for example
for(int i = 0; i < 100000000L; i++){
myHugeCalc(i);
final int prog = i;
runOnUiThread(new Runnable() {
                    public void run() {

                        pbtext.setText("My progress: " + prog);

                    }
                });
}

}).start();

Upvotes: 1

Ashwani
Ashwani

Reputation: 1304

There is another way to do so... when you are calling this sync process from your class, start showing the progress dialog there, and onPostExecute cancel it. It will do your work... but the best practise is to do it in onPreExecute

Upvotes: 0

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