android - 为了许多有趣的论点Fragment.findNavController()

Question

import android.os.Bundle
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.databinding.DataBindingUtil
import androidx.drawerlayout.widget.DrawerLayout
import com.example.tender.R
import com.example.tender.databinding.FragmentAvailableTenderBinding
import com.example.tender.databinding.FragmentLoginBinding
import androidx.navigation.fragment.findNavController
import androidx.navigation.ui.NavigationUI

/**
 * A simple [Fragment] subclass.
 */
class AvailableTenderFragment : Fragment() {

    private lateinit var drawerLayout: DrawerLayout

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {

        val binding = FragmentAvailableTenderBinding.inflate(inflater)

        drawerLayout = binding.drawerLayout

        **val navController = this.findNavController(R.id.nav_host_fragment)**

        **NavigationUI.setupActionBarWithNavController(this, navController, drawerLayout)**

        NavigationUI.setupWithNavController(binding.navView, navController)

        binding.root

    }
}

当我将鼠标悬停在findnavcontroller上时，显示“在androidx.navigation.fragment中定义的许多有趣的Fragment.findNavController():NAvcontroller”。我无法解决以上粗体行中的错误。在这种情况下，我该怎么办？

Answer 1

按照Navigate to a destination documentation，导入的androidx.navigation.fragment.findNavController不带任何参数(它会找到当前Fragment的父NavHostFragment，并且不需要NavHostFragment的ID)。

您编写的行(即findNavController(R.id.nav_host_fragment)和setupActionBarWithNavController())是您要在Activity中(而不是在Fragment中)调用的方法。