Question

For a few days a have some problem.
I need to show simple ProgressBar (not dialog) while doing some stuff in main thread…
I thought its a very simple question, but i cant do this, help me please.

First i tried simple setVisibility(View.VISIBLE) before and setVisibility(View.GONE) after.

But this is doing in the same thread, and ProgressBar freezed while my function working.

Now i have this code, but i have some error, and i dont know whats wrong..

my simple layout :

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
<ProgressBar
    android:id="@+id/loading"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:visibility="gone" />
</FrameLayout>

i have a base activity :

public class BaseActivity extends Activity {
    public ProgressBar loading;

    public class ProgressBarShow extends AsyncTask<Void, Void, Void> {
    protected Void doInBackground(Void... unused) {
        return(null);
    }

    protected void onProgressUpdate() {
    }
    protected void onPreExecute() {
        loading.setVisibility(View.VISIBLE);
    }

    protected void onPostExecute() {
    }
   }
}

and finally my working activity , which extends BaseActivity

public class SearchActivity extends BaseActivity {
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
        loading = (ProgressBar) findViewById(R.id.loading);

        new ProgressBarShow().execute();
        //doing long stuff
        //new ProgressBarHide().execute(); there isnt, but sense the same
    }
}

I have many activities, which need progress bar, thats why i have created BaseActivity,
to not to dublicate code.

I need to do long work (stuff function) in main thread, because i want to freeze main window and not to allow user do anything (click button etc..), just show working ProgressBar.

Whats wrong in my example? Or give me some advice how can i do this better

Answer 1

class ProgressTask extends AsyncTask<Integer, Integer, Void>{
    ProgressBar progress;
    Context context;
    public ProgressTask(ProgressBar progress, Context context) {
        this.progress = progress;
        this.context = context;

    }
    @Override
    protected void onPreExecute() {
        // initialize the progress bar
        // set maximum progress to 100.
        progress.setMax(100);

    }


    @Override
    protected Void doInBackground(Integer... params) {
        // get the initial starting value
        int start=params[0];


        // increment the progress
        for(int i=start;i<=100;i+=5){
            try {
                boolean cancelled=isCancelled();
                //if async task is not cancelled, update the progress
                if(!cancelled){
                    publishProgress(i);
                    SystemClock.sleep(1000);

                }

            } catch (Exception e) {
                Log.e("Error", e.toString());
            }

        }
        return null;
    }
    //Has direct connection to UI Main thread
    //Called everytime publishProgress(int) is called in doInBackground
    @Override
    protected void onProgressUpdate(Integer... values) {
        progress.setProgress(values[0]);
        Toast.makeText(context, "test"+values[0], Toast.LENGTH_SHORT).show();
    }


    @Override
    protected void onPostExecute(Void result) {
        // async task finished
                    Log.v("Progress", "Finished");
    }
    @Override
    protected void onCancelled() {
        progress.setMax(0);
    }
}