Fetch data in background and display in UI

Question

I'm using volley to fetch data using volley and display in User Interface, and it takes time to load the data. What i want to happen is, I want to fetch the data in background during the splash screen or loading screen and display it in User interface. I want the fetching part to be done in another activity and it should be a background service and this should be called in "main activity" to populate the fields.

Use `MVVM` pattern or `Rxandroid`, it will help you in reactive programming — Farhana Naaz Ansari, Aug 02 '18 at 07:16

score 0 · Answer 1 · answered Aug 02 '18 at 07:18

use AsyncTask like that

 private class LongOperation extends AsyncTask<String, Void, String>
   {

    @Override
    protected String doInBackground(String... params)
    {
       //do your work here 


        return "Executed";
    }

    @Override
    protected void onPostExecute(String result)
    {
        progressBar.dismiss();

    }

    @Override
    protected void onPreExecute()
    {
        progressBar = ProgressDialog.show(getActivity(), null, "message...");
        progressBar.show();
    }

    @Override
    protected void onProgressUpdate(Void... values)
    {
    }
}

Anže Mur · Accepted Answer · 2018-08-02T07:34:05.920

0

You can try using the AsyncTask. So the process goes like that:

In onPreExecute() you can show a ProgresDialog or a ProgresBar to visualize your loading process
in doInBackground(Params...) you start loading your data
and in onPostExecute(Result) you display your data in UI and hide your ProgresDialog/ProgresBar.

Example of AsyncTask usage.

Do it like this:

private class LoadDataBaseData extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... params) {
        //Start loading your data 

        return "Data loaded";
    }

    @Override
    protected void onPostExecute(String result) {
       //Update your UI with data you loaded/start your activity with loaded data

    }

    @Override
    protected void onPreExecute(){     
    }

    @Override
    protected void onProgressUpdate(Void... values) {
    }
}

edited Aug 02 '18 at 07:34

answered Aug 02 '18 at 07:19

Anže Mur

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The thing is i don't want to display any ProgressBar . when i click a button it shows updating and displays the data . the delay is 5 seconds. all i want to do is , when app starts , start loading the data in another activity and when the button is pressed display the data acquired instantly . No delay. Do the fetching part in background. – Sam Sundar Aug 02 '18 at 07:26
You can still do that with AsyncTask, ProgresBar/Dialog is just optional so it blocks UI for the time that data is loading. Use AsyncTask to load it, like I told you and just don't use any ProgresBars. You can start your AsyncTask OnCreate or OnStart and it should be OK. – Anže Mur Aug 02 '18 at 07:29
I added an example that would suit your needs. – Anže Mur Aug 02 '18 at 07:34

Fetch data in background and display in UI

2 Answers2