微调器在我的 Kotlin 片段中不起作用

Question

我想要一个微调器出现，让用户在两种类型之间进行选择，但它不起作用

  inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
       spinner2?.adapter = ArrayAdapter(activity, R.layout.support_simple_spinner_dropdown_item, types) as SpinnerAdapter
        spinner2?.onItemSelectedListener = object :AdapterView.OnItemSelectedListener{
            override fun onNothingSelected(parent: AdapterView<*>?) {
                println("erreur")
            }

            override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
                val type = parent?.getItemAtPosition(position).toString()
                println(type)
            }

        }
        return inflater.inflate(R.layout.fragment_add, container, false)
    }

Answer 1

解决方法是activity?.applicationContext在adapter中添加将activityFragment改为context：

class Add : Fragment()
{

val types = arrayOf("simple User", "Admin")

override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val t=inflater.inflate(R.layout.fragment_add, container, false)
        val spinner = t.findViewById<Spinner>(R.id.spinner2)
       spinner?.adapter = ArrayAdapter(activity?.applicationContext, R.layout.support_simple_spinner_dropdown_item, types) as SpinnerAdapter
        spinner?.onItemSelectedListener = object :AdapterView.OnItemSelectedListener{
            override fun onNothingSelected(parent: AdapterView<*>?) {
                println("erreur")
            }

            override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
                val type = parent?.getItemAtPosition(position).toString()
                Toast.makeText(activity,type, Toast.LENGTH_LONG).show()
                println(type)
            }

        }
        return t
    }
}