微調器不起作用,我嘗試了不同版本的代碼,但在其中任何一個都不起作用
任何人都可以幫助解決這個問題嗎?
轉移片段
package com.example.hotel2.transfer
class TransferFragment : Fragment(){
private var _binding: FragmentTransferBinding? = null
private val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
_binding = FragmentTransferBinding.inflate(inflater, container, false)
val view = binding.root
return view
val transfers = arrayOf<String>("Flowers", "Candies")
val adapter: ArrayAdapter<String> =
ArrayAdapter<String>(activity?.applicationContext!!, android.R.layout.simple_spinner_item, transfers)
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
val spinner = binding.spinner
spinner.adapter = adapter
spinner.prompt = "Title"
spinner.setOnItemSelectedListener(object : AdapterView.OnItemSelectedListener {
override fun onItemSelected(
parent: AdapterView<*>?, view: View?,
position: Int, id: Long
) {
}
override fun onNothingSelected(arg0: AdapterView<*>?) {}
})
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
片段傳輸.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".transfer.TransferFragment">
<Spinner
android:id="@ id/spinner"
android:layout_width="200dp"
android:layout_height="wrap_content"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="300dp"
android:layout_marginStart="50dp"></Spinner>
</androidx.constraintlayout.widget.ConstraintLayout>
根據我的猜測,問題出在activity?.applicationContext!!,但我不明白如何解決
uj5u.com熱心網友回復:
在onCreateView()您將此陳述句作為方法中的第 4 條陳述句:
return view
此陳述句之后的所有代碼都不會執行。
有趣的是,您的 IDE(Android Studio 或其他)應該會告訴您這一點!
轉載請註明出處,本文鏈接:https://www.uj5u.com/yidong/481004.html
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