@TargetApi(11)
    public void setNavigationBarAlpha(float alpha) {
        if (mNavBarAvailable && Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            mNavBarTintView.setAlpha(alpha);
        }
    }
@ TargetApi ( 11 ) public void setNavigationBarAlpha ( float alpha ) { if ( mNavBarAvailable && Build . VERSION . SDK_INT >= Build . VERSION_CODES . HONEYCOMB ) { mNavBarTintView . setAlpha ( alpha ) ; } }
Apply the specified alpha to the system navigation bar.

@param alpha The alpha to use