CODEWITHSUNDEEP
androidxmllayout
Mxyk
Mxyk

Reputation: 10698

Android Won't Display A Layout

I recently discovered that since my app is pulling so much data from a few URLs, it takes about 3-7 seconds for it to load the main layout. So, I made a layout called 'loading' to display, which is just simply a TextView that states "Please wait while data is being collected...". However, when I run my app, it won't display the 'loading' layout. It simply goes black for a while, like it used to before, and then go to the main layout. I tried cleaning the project too, and it still does this. Here's a portion of my Main.java:

@Override
public void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.loading);
    populateArray();
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // Set up click listeners for all buttons
    View v1 = findViewById(R.id.continueButton);
    v1.setOnClickListener(this);

    View v2 = findViewById(R.id.colorCheck);
    v2.setOnClickListener(this);

    View v3 = findViewById(R.id.terms);
    v3.setOnClickListener(this);
}

populateArray(); is the method that is pulling all the information of the internet. So, I figured, "Why not tell it to set the content view immediately to 'loading', have it run populateArray();, then display the main layout?" Obviously, I must be missing something here. Any ideas?

==========================================================================

EDIT: I tried using AsyncTask, but I'm getting a force close. I'm also getting a warning saying the AsyncTask class is never used. Here's my code:

P.S. ProgressDialog dialog; is a global definition.

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        dialog = ProgressDialog.show(this, "",
                "Please wait while data is collected...", true);

        // Set up click listeners for all buttons
        View v1 = findViewById(R.id.continueButton);
        v1.setOnClickListener(this);

        View v2 = findViewById(R.id.colorCheck);
        v2.setOnClickListener(this);

        View v3 = findViewById(R.id.terms);
        v3.setOnClickListener(this);
    }

And...

    private class LoadData extends AsyncTask <String[][], String, String> {
        @Override
        protected String doInBackground(String[][]... voidThisArray) {
            String voidThisString = null;
            populateArray();
            return voidThisString;
        }

        @Override
        protected void onPostExecute(String voidThisString) {
            setContentView(R.layout.main);
            dialog.dismiss();
        }

    }

I would give you the LogCat for the force close but for some reason the LogCat isn't displaying anything...

Upvotes: 1

Views: 503

Answers (3)

ahodder
ahodder

Reputation: 11439

You want to use an AsyncTask to first: create a ProgressDialog that will display the loading message. Then the AsyncTask will work in the background collecting all of the data.

Hope that helps.

private class Task extends AsyncTask<Void,Integer, Void> {
    private ProgressDialog dia;

    @Override protected void onPreExecute() {
        dia = new ProgressDialog(MyContext.this);
        dia.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        dia.setMessage("Loading. Please wait...");
        dia.setCancelable(false);
        dia.show();

                // Set up preserver download stuff
        }

    @Override protected Void doInBackground(Void... voids) {
        // perform server download stuff
    }

    @Override public void onProgressUpdate(Integer... prog) {
        if (prog == null)
            return;
        dia.setProgress(prog[0]);
    }

    @Override  protected void onPostExecute(Void voids) {
        // Do any post op stuff
        dia.cancel();
    }
}

Upvotes: 3

Gopal
Gopal

Reputation: 1719

Look at AsyncTask and execute 

populateArray();

in doInBackground method of AsyncTask.

And call 

setContentView

only once you can show loading by using onPreExecute and onPostExecute method of AsyncTask

Upvotes: 2

Jack
Jack

Reputation: 9242

You should see this page for information about threading. Basically if your application is going to do any long running operation, you want it in a thread. Your UI is locking up because your performing this operation on your UI thread.

As far as progress updates, I personally use a ProgressDialog to show when something is happening, although you could build a custom view to indicate this.

Upvotes: 2

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