（activity或弹出弹框时）隐藏底部导航栏

dialog中的使用

window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
window.decorView.setOnSystemUiVisibilityChangeListener {
            var uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_STABLE or  //布局位于状态栏下方
                    View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION or  //全屏
                    View.SYSTEM_UI_FLAG_FULLSCREEN or  //隐藏导航栏
                    View.SYSTEM_UI_FLAG_HIDE_NAVIGATION or
                    View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
            uiOptions = uiOptions or 0x00001000
            window.decorView.systemUiVisibility = uiOptions
        }

activity中在 onResume()方法中调用 hideBottomNavigation()

    /**
     * 隐藏底部虚拟按键
     */
    fun hideBottomNavigation(activity: AppCompatActivity) {
     activity.window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
     activity.window.decorView.setOnSystemUiVisibilityChangeListener {
            var uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_STABLE or  //布局位于状态栏下方
                    View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION or  //全屏
                    View.SYSTEM_UI_FLAG_FULLSCREEN or  //隐藏导航栏
                    View.SYSTEM_UI_FLAG_HIDE_NAVIGATION or
                    View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
            uiOptions = uiOptions or 0x00001000
            activity.window.decorView.systemUiVisibility = uiOptions
        }
    }