Android开发 判断目标Fragment是否在前台

    /**
     * [fragmentClass]是否是活跃Fragment
     */
    public fun <F : Fragment> isActiveFragment(fragmentClass: Class<F>): Boolean {
        val navHostFragment = this.supportFragmentManager.fragments.first() as NavHostFragment
        navHostFragment.childFragmentManager.fragments.forEach {
            if (fragmentClass.isAssignableFrom(it.javaClass)) {
                return true
            }
        }
        return false
    }