数组需要什么格式才能让微调器正确使用它？

Question

我的应用中有一个微调器，应该填充供应商列表。微调器最初来自一些示例代码，并且使用示例中的固定字符串完美地工作。但是，就我而言，我从 API 获取值（供应商）列表。我可以看到 API 被正确调用以及 Logcat 中返回的数据。我想从此响应中获取数据并将其用作我的微调器的对象列表。

我的问题有两个。是否有更直接的方式将响应转换为适配器，如果没有，我如何将读取响应转换为微调器将使用的内容？

我的意图代码如下所示：

<?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=".AddNewSupplier">

    <TextView
        android:id="@+id/lblSupplierName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="12dp"
        android:layout_marginTop="24dp"
        android:text="Supplier Name"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Spinner
        android:id="@+id/spinSelectSupplier"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="@+id/lblSupplierName"
        app:layout_constraintStart_toStartOf="@+id/txtSupplierName"
        app:layout_constraintTop_toTopOf="@+id/lblSupplierName" />
</androidx.constraintlayout.widget.ConstraintLayout>

班级是：

class AddNewSupplier : AppCompatActivity() {
    private lateinit var lblSupplierName: TextView
    private lateinit var spinSelectSupplier: Spinner

    var aSups: MutableList<String> = ArrayList()
    var strSups: String = ""
    var arrSuppliers = arrayOf("")

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_add_new_supplier)

    lblSupplierName = findViewById(R.id.lblSupplierName)

    spinSelectSupplier = findViewById(R.id.spinSelectSupplier)

    loadSupplierList()

    var list_of_items = arrayOf(strSups)

    if (spinSelectSupplier != null) {
        val adapter = ArrayAdapter(this,
            android.R.layout.simple_spinner_item, list_of_items)
        spinSelectSupplier.adapter = adapter
        spinSelectSupplier.onItemSelectedListener = object :
            AdapterView.OnItemSelectedListener {
            override fun onItemSelected(parent: AdapterView<*>,
                                        view: View, position: Int, id: Long) {
                Log.d("Seld: ", aSups[position].toString())
            }

            override fun onNothingSelected(parent: AdapterView<*>) {
                // write code to perform some action
            }
        }
    }
}

private fun loadSupplierList() {
    AllSuppliers.create().getAllSuppliers("all").enqueue(object : Callback<SupplierList> {

        override fun onFailure(call: Call<SupplierList>, t: Throwable) {
            Log.d("Error :: ", t.localizedMessage!!)
            t.printStackTrace()
        }

        override fun onResponse(
            call: Call<SupplierList>,
            response: Response<SupplierList>
        ) {
            Log.d("AllSuppliers :: ", response.body().toString())
            val suppliers = response.body()?.APIResult!![0]

            for (i in 0..suppliers.suppliers.size - 1) {
                Log.d("Each: ", suppliers.suppliers[i].supplier_name)

                aSups.add(suppliers.suppliers[i].supplier_name)
                strSups += ", \"" + suppliers.suppliers[i].supplier_name + "\""
            }
            strSups = strSups.subSequence(1, strSups.length).toString()
            Log.d("StrArr:", strSups)
            Log.d("ArrElem:", aSups[1].toString())
        }
    })
  }
}

为获取供应商而调用的 API 返回 3 个供应商，我可以在循环中看到每个供应商，因此我知道此时响应已完全返回。

我尝试将供应商附加到数组 aSup 中，但这对微调器不起作用（微调器为空），尽管我可以愉快地读取元素 1。我什至尝试构建一个字符串 (list_of_items) 给我“供应商 1”、“供应商 2”等，因为这与我从中获取代码的工作示例相同，但我仍然得到一个空数组。有人可以解释一下我做错了什么吗？

Answer 1

在调用loadSupplierList() 后尝试填充微调器。我的意思是确保strSups 不为空。尝试在onResponse() 方法中填充微调器。 像这样：

class AddNewSupplier : AppCompatActivity() {
    private lateinit var lblSupplierName: TextView
    private lateinit var spinSelectSupplier: Spinner

    var aSups: MutableList<String> = ArrayList()
    var strSups: String = ""
    var arrSuppliers = arrayOf("")

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_add_new_supplier)

    lblSupplierName = findViewById(R.id.lblSupplierName)

    spinSelectSupplier = findViewById(R.id.spinSelectSupplier)

    loadSupplierList()    
   
}

private fun loadSupplierList() {
    AllSuppliers.create().getAllSuppliers("all").enqueue(object : Callback<SupplierList> {

        override fun onFailure(call: Call<SupplierList>, t: Throwable) {
            Log.d("Error :: ", t.localizedMessage!!)
            t.printStackTrace()
        }

        override fun onResponse(
            call: Call<SupplierList>,
            response: Response<SupplierList>
        ) {
            Log.d("AllSuppliers :: ", response.body().toString())
            val suppliers = response.body()?.APIResult!![0]

            for (i in 0..suppliers.suppliers.size - 1) {
                Log.d("Each: ", suppliers.suppliers[i].supplier_name)

                aSups.add(suppliers.suppliers[i].supplier_name)
                strSups += ", \"" + suppliers.suppliers[i].supplier_name + "\""
            }
            strSups = strSups.subSequence(1, strSups.length).toString()
            Log.d("StrArr:", strSups)
            Log.d("ArrElem:", aSups[1].toString())
           
            // call the new method here
            fillSpinner()
        }
    })
  }

  private fun fillSpinner(){

      var list_of_items = arrayOf(strSups)
      if (spinSelectSupplier != null) {
        val adapter = ArrayAdapter(this,
            android.R.layout.simple_spinner_item, list_of_items)
        spinSelectSupplier.adapter = adapter
        spinSelectSupplier.onItemSelectedListener = object :
            AdapterView.OnItemSelectedListener {
            override fun onItemSelected(parent: AdapterView<*>,
                                        view: View, position: Int, id: Long) {
                Log.d("Seld: ", aSups[position].toString())
            }

            override fun onNothingSelected(parent: AdapterView<*>) {
                // write code to perform some action
            }
        }
    }      


  }

}