How to change current Theme at runtime in Android [duplicate]

Answer 1

I had a similar problem and I solved in this way..

@Override
public void onCreate(Bundle savedInstanceState) {

    if (getIntent().hasExtra("bundle") && savedInstanceState==null){
        savedInstanceState = getIntent().getExtras().getBundle("bundle");
    }

    //add code for theme

    switch(theme)
    {
    case LIGHT:
        setTheme(R.style.LightTheme);
        break;
    case BLACK:
        setTheme(R.style.BlackTheme);
        break;

    default:
    }
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //code

}

this code is for recreate the Activity saving Bundle and changing the theme. You have to write your own onSaveInstanceState(Bundle outState); From API-11 you can use the method recreate() instead

Bundle temp_bundle = new Bundle();
onSaveInstanceState(temp_bundle);
Intent intent = new Intent(this, MainActivity.class);
intent.putExtra("bundle", temp_bundle);
startActivity(intent);
finish();

Answer 2

I would like to see the method too, where you set once for all your activities. But as far I know you have to set in each activity before showing any views.

For reference check this:

http://www.anddev.org/applying_a_theme_to_your_application-t817.html

Edit (copied from that forum):

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

        // Call setTheme before creation of any(!) View.
         setTheme(android.R.style.Theme_Dark);

        // ...
        setContentView(R.layout.main);
    }

Edit
If you call setTheme after super.onCreate(savedInstanceState); your activity recreated but if you call setTheme before super.onCreate(savedInstanceState); your theme will set and activity does not recreate anymore

  protected void onCreate(Bundle savedInstanceState) {
     setTheme(android.R.style.Theme_Dark);
     super.onCreate(savedInstanceState);


    // ...
    setContentView(R.layout.main);
}

Answer 3

i got the same problem but i found the solution.

public class EditTextSmartPhoneActivity extends Activity implements DialogInterface.OnClickListener
{
    public final static int CREATE_DIALOG  = -1;
    public final static int THEME_HOLO_LIGHT  = 0;
    public final static int THEME_BLACK  = 1;

    int position;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        position = getIntent().getIntExtra("position", -1);

        switch(position)
        {
        case CREATE_DIALOG:
            createDialog();
            break;
        case THEME_HOLO_LIGHT:
            setTheme(android.R.style.Theme_Holo_Light);
            break;
        case THEME_BLACK:
            setTheme(android.R.style.Theme_Black);
            break;
        default:
        }

        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

    }

    private void createDialog()
    {
        /** Options for user to select*/
        String choose[] = {"Theme_Holo_Light","Theme_Black"};

        AlertDialog.Builder b = new AlertDialog.Builder(this);

        /** Setting a title for the window */
        b.setTitle("Choose your Application Theme");

        /** Setting items to the alert dialog */
        b.setSingleChoiceItems(choose, 0, null);

        /** Setting a positive button and its listener */
        b.setPositiveButton("OK",this);

        /** Setting a positive button and its listener */
        b.setNegativeButton("Cancel", null);

        /** Creating the alert dialog window using the builder class */
        AlertDialog d = b.create();

        /** show dialog*/
        d.show();
    }

    @Override
    public void onClick(DialogInterface dialog, int which) {
        // TODO Auto-generated method stub
        AlertDialog alert = (AlertDialog)dialog;
        int position = alert.getListView().getCheckedItemPosition();

        finish();
        Intent intent = new Intent(this, EditTextSmartPhoneActivity.class);
        intent.putExtra("position", position);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(intent);
    }
}

Answer 4

We have to set theme before calling 'super.onCreate()' and 'setContentView()' method.

Check out this link for applying new theme to whole application at runtime.

Answer 5

recreate() (as mentioned by TPReal) will only restart current activity, but the previous activities will still be in back stack and theme will not be applied to them.

So, another solution for this problem is to recreate the task stack completely, like this:

    TaskStackBuilder.create(getActivity())
            .addNextIntent(new Intent(getActivity(), MainActivity.class))
            .addNextIntent(getActivity().getIntent())
            .startActivities();

EDIT:

Just put the code above after you perform changing of theme on the UI or somewhere else. All your activities should have method setTheme() called before onCreate(), probably in some parent activity. It is also a normal approach to store the theme chosen in SharedPreferences, read it and then set using setTheme() method.

Answer 6

Call SetContentView(Resource.Layout.Main) after setTheme().