Android Show Soft Keyboard When First Activity Starts?

I need to display the virtual keyboard when the application starts, but so far I've failed.

I use this code in method "OnCreate"to display the virtual keyboard

    InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.toggleSoftInput(txtBuscar.getId(), InputMethodManager.SHOW_FORCED);

this code works fine on any screen at any time, but does not work when the "first" activity begins. Why?

I tried it when I start another activity and it works, but does not work when I start the "first"activity.

I tried to put this code in the events "OnCreate"and many more .... but it seems not work.

is there anyway to "force" to display the keyboard when I start the application?

Thanks in advance.

I Found the solution:

txtPassword.postDelayed(new Runnable() {
            @Override
            public void run() {
                InputMethodManager keyboard = (InputMethodManager)
                getSystemService(Context.INPUT_METHOD_SERVICE);
                keyboard.showSoftInput(txtPassword, 0); 
            }
        },200);

Thanks !!!