Kotlin中如何从多层页面栈直接返回主菜单Activity

我有一个主菜单Activity，用户可从中进入多个不同功能模块。点击对应按钮会跳转至目标Activity，随后该Activity会打开多个Fragment。我希望用户在任意时点点击Done按钮都能直接返回主菜单，但目前点击后仅能返回当前Activity的首个Fragment，是不是我对Activity>Activity>Fragments的栈处理逻辑有误？

主菜单Activity代码 #

binding.putaway.setOnClickListener {
    val intent = Intent(this, PutAwayMainActivity::class.java)
    startActivity(intent)
}
binding.cyclecount.setOnClickListener {
    val intent = Intent(this, CycleCountMainActivity::class.java)
    startActivity(intent)
}
binding.transfer.setOnClickListener {
    val intent = Intent(this, TransferMainActivity::class.java)
    startActivity(intent)
}
binding.itemlookup.setOnClickListener {
    val intent = Intent(this, ItemLookupMainActivity::class.java)
    startActivity(intent)
}
binding.newreceipt.setOnClickListener {
    val intent = Intent(this, NewReceiptMainActivity::class.java)
    startActivity(intent)
}
binding.additem.setOnClickListener {
    val intent = Intent(this, NewReceiptAddItemMainActivity::class.java)
    startActivity(intent)
}

NewReceiptMainActivity代码 #

class NewReceiptMainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_new_receipt_main)

        val fragment = NewReceiptSelectProgram()
        val fram = supportFragmentManager.beginTransaction()
        fram.replace(R.id.nav_newreceipt_fragment,fragment)
        fram.commit()
    }
}

当前尝试的返回逻辑（仅返回首个Fragment） #

private fun donePressed() {
    parentFragmentManager.popBackStackImmediate(null, FragmentManager.POP_BACK_STACK_INCLUSIVE)
}

解决方案 #

问题核心是你只操作了Fragment栈，没有处理Activity栈。popBackStackImmediate只会清空当前Activity内的Fragment栈，但当前Activity仍处于系统的Activity栈中，所以退到首个Fragment后就无法继续返回。

要直接回到主菜单，只需销毁当前的功能模块Activity：

最简实现 #

private fun donePressed() {
    requireActivity().finish()
}

可选：先清Fragment栈再销毁Activity #

如果需要确保Fragment资源也被清理，可以先清空Fragment栈再结束Activity（通常finish()已足够）：

private fun donePressed() {
    parentFragmentManager.popBackStackImmediate(null, FragmentManager.POP_BACK_STACK_INCLUSIVE)
    requireActivity().finish()
}

内容的提问来源于stack exchange，提问作者btorkelson