Showing launcher screen only once in Android

Question

I want to show launcher screen in Android app only once. Then if the user is on the second screen, if he presses back button, I want app to close. What's wrong in this code? The first screen shows again, what mustn't be.

public class MainActivity extends Activity {

    private boolean firstscreenshown=false; 

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        if (firstscreenshown==true) finish();
        firstscreenshown=true;

or

public class MainActivity extends Activity {

    private boolean firstscreenshown; 

    public MainActivity() {
        this.firstscreenshown = false;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        if (firstscreenshown==true) finish();
        firstscreenshown=true;

Answer 1

Use this code for handle back button in your MainActivity class:

@Override
    public void onBackPressed()
        {
            // TODO Auto-generated method stub
            super.onBackPressed();
            Intent startMain = new Intent(Intent.ACTION_MAIN);
            startMain.addCategory(Intent.CATEGORY_HOME);
            startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivity(startMain);
        }

Answer 2

I have a disclaimer view that I display the first time my app is run. Here is how I handle it:

public class MainActivity extends Activity {

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

    // check preferences to see if disclaimer has been display
    boolean showDisclaimer = getPreferences(MODE_PRIVATE).getBoolean("disclaimer", true);
    if (showDisclaimer) {

        // turn off the disclaimer
        getPreferences(MODE_PRIVATE).edit().putBoolean("disclaimer",false).commit();

        // display the disclaimer
        Intent intent = new Intent(MainActivity.this, LegalActivity.class);
        startActivity(intent);
    }

    setContentView(R.layout.activity_main);
}

Here is the activity for the disclaimer:

public class LegalActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.legal_detail);

    // Watch for guide button clicks.
    Button button = (Button) this.findViewById(R.id.legal_button);
    button.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            finish();
        }
    });
}

My disclaimer view has a done button which closes it.

Hope this helps!

Answer 3

Call finish after your call to the second activity, so when the second screen appears the previous one will be erased.

startActivity(intent)

Answer 4

The best and simplest way to achieve this would be to override onPause() method and call :

finish();

inside the first activity!