CODEWITHSUNDEEP
androidandroid-fragmentsandroid-activity
Denys
Denys

Reputation: 4557

sequence of activity flows in android fragments app

Here are some facts about my app followed by a question

My app has two fragments.

My app creates certain file structure and documents on its first launch and it takes time, thus I am using AsyncTask class method to display ProgressDialog while the file structure is created. This is done in onCreate method of my MainActivity just like this: 

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        progress = new ProgressDialog(this);
        progress.setMessage("Loading...");

        File testFile = new File("/mnt/sdcard/myNewFolder");
        if (!testFile.exists()) {
            new MyTask(progress).execute();
            setContentView(R.layout.activity_main);
        } else
            setContentView(R.layout.activity_main);
    }

The problem is that onActivityCreated method of one of my Fragments starts running BEFORE new MyTask(progress).execute(); is finished. This causes errors and problems.

Why this onActivityCreated method of one of my Fragments runs BEFORE
new MyTask(progress).execute();???

Please do not assume that there are some silly mistakes that i didnt take into account xx

This is my MyTask class

public class MyTask extends AsyncTask<Void, Void, Void> {
    public MyTask(ProgressDialog progress) {
        // this.progress = progress;
    }

    public void onPreExecute() {
        progress.show();
    }

    public void onPostExecute(Void unused) {
        progress.dismiss();
    }

    @Override
    protected Void doInBackground(Void... params) {
        CreateFileStructure();
        return null;
    }
}

I need to create that file structure before anything else happens - that is why I am using this ProgressDialog. What am I doing wrong?

Upvotes: 0

Views: 816

Answers (2)

Denys
Denys

Reputation: 4557

Here is the code that works for me - the ProgressDialog dialog is displayed while file structure and files are created, everything else (fragments, etc.) happens afterwards. 

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        progress = new ProgressDialog(this);
        progress.setMessage("Loading...");

        File testFile = new File("/mnt/sdcard/myNewFolder");
        if (!testFile.exists())
            new MyTask(progress).execute();
        else
            setContentView(R.layout.activity_main);
    }

    public class MyTask extends AsyncTask<Void, Void, Void> {
        public MyTask(ProgressDialog progress) {
            // this.progress = progress;
        }

        public void onPreExecute() {
            progress.show();
        }

        public void onPostExecute(Void unused) {

            progress.dismiss();
            setContentView(R.layout.activity_main);
        }

        @Override
        protected Void doInBackground(Void... params) {
            CreateFileStructure();
            return null;
        }
    }

Upvotes: 0

Chinmoy Debnath
Chinmoy Debnath

Reputation: 2824

If you see the life cycle of fragment, the view of the fragment's are instantiated on the onCreate method of the activity which contains the fragment.

For that reason you are getting that error.

Upvotes: 1

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