我一直在学习安卓工作室的课程，但我偶然发现了这个特定方法的问题。无论出于什么原因，我都可以在每个片段中使用它，除了一个片段，其中显然无法导入。
这是片段：(StartFragment(
package com.example.cupcake
import android.app.Fragment
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.navigation.fragment.findNavController
import com.example.cupcake.databinding.FragmentStartBinding
/**
* This is the first screen of the Cupcake app. The user can choose how many cupcakes to order.
*/
class StartFragment : Fragment() {
// Binding object instance corresponding to the fragment_start.xml layout
// This property is non-null between the onCreateView() and onDestroyView() lifecycle callbacks,
// when the view hierarchy is attached to the fragment.
private var binding: FragmentStartBinding? = null
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val fragmentBinding = FragmentStartBinding.inflate(inflater, container, false)
binding = fragmentBinding
return fragmentBinding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
binding?.apply {
// Set up the button click listeners
orderOneCupcake.setOnClickListener { orderCupcake(1) }
orderSixCupcakes.setOnClickListener { orderCupcake(6) }
orderTwelveCupcakes.setOnClickListener { orderCupcake(12) }
}
}
/**
* Start an order with the desired quantity of cupcakes and navigate to the next screen.
*/
fun orderCupcake(quantity: Int) {
findNavController().navigate(R.id.action_startFragment_to_flavorFragment) //here is the error
}
/**
* This fragment lifecycle method is called when the view hierarchy associated with the fragment
* is being removed. As a result, clear out the binding object.
*/
override fun onDestroyView() {
super.onDestroyView()
binding = null
}
}
整个代码都在代码链接中，感谢
您的片段扩展了android.app.Fragment——这是不推荐使用的，永远不应该使用的框架片段。您需要将import android.app.Fragment替换为import androidx.fragment.app.Fragment，以实际扩展需要与Navigation一起使用的AndroidX片段。