slider - ArrayAdapter OnItemSelectedListener 不起作用

Question

我创建了一个 arrayAdapter 来显示 MaterialDropdownMenu 中的项目，我希望 TextView 将文本设置为所选项目，但文本永远不会改变。为什么不这样做？谢谢

这里是 Kotlin 文件：

    val options = arrayOf("Item 1", "Item 2", "Item 3")
    val arrayAdapter = ArrayAdapter(this, R.layout.options_slider, options)
    autoOptions.setText(arrayAdapter.getItem(0).toString(),false)
    autoOptions.setAdapter(arrayAdapter)

    autoOptions.onItemSelectedListener = object : AdapterView.OnItemSelectedListener{
        override fun onNothingSelected(parent: AdapterView<*>?) {

        }

        override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {

            tv1.text=options[position]
        }

    }

和xml文件：

<com.google.android.material.textfield.TextInputLayout
        android:id="@+id/menu"
        style="@style/Widget.MaterialComponents.TextInputLayout.FilledBox.ExposedDropdownMenu"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Settings">

        <AutoCompleteTextView
            android:id="@+id/autoOptions"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:inputType="none"
            />

        <TextView
        android:id="@+id/tv1"
        android:layout_width="300dp"
        android:layout_height="25dp"
        android:text="test"
        android:textAlignment="center">

    </TextView>

    </com.google.android.material.textfield.TextInputLayout>

这里是options_slider的xml文件：

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ellipsize="end"
    android:padding="16dp"
    android:maxLines="1"
    android:textAppearance="?attr/textAppearanceSubtitle1">

</TextView>

标签： slidermaterial-designandroid-arrayadapterautocompletetextviewonitemselectedlistener