Clicking hamburger icon on Toolbar does not open Navigation Drawer

Question

I have a simple android.support.v7.widget.Toolbar and all I am trying to do is to open a NavigationDrawer by pressing the \"hamburger\" icon in the top left cor

Answer 1

While accepted answer here works alright however, as they say "Prevention is better than cure".. Adding mDrawerToggle.syncState(); in onPostCreate and onConfigurationChanged() wroks much better as answerd by @mbmc above:

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    // Sync the toggle state after onRestoreInstanceState has occurred.
    mDrawerToggle.syncState();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    mDrawerToggle.onConfigurationChanged(newConfig);
}