MainActivity.kt 中的"未解析引用"调用 TextView?

Question

当我尝试在activity_main.xml中使用TextView时，我在MainActivity.kt中得到了一个"未解析的引用"(甚至在尝试构建之前)？我只是看不出我做错了什么！

我已经在主活动结束时突出显示了错误。

任何帮助表示赞赏。

MainActivity.kt

class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val carouselRecyclerview = findViewById<CarouselRecyclerview>(R.id.recycler)
val list = ArrayList<DataModel>()
list.add(DataModel(R.drawable.ad_astra, "Adastra"))
list.add(DataModel(R.drawable.beach_bum, "Beach Bum"))
list.add(DataModel(R.drawable.dark_phoenix, "Dark Phoenix"))
list.add(DataModel(R.drawable.glass, "Glass"))
val adapter = DataAdapter(list)
carouselRecyclerview.adapter = adapter
carouselRecyclerview.set3DItem(true)
carouselRecyclerview.setAlpha(true)
val carouselLayoutManager = carouselRecyclerview.getCarouselLayoutManager()
val currentlyCenterPosition = carouselRecyclerview.getSelectedPosition()
carouselRecyclerview.setItemSelectListener(object : CarouselLayoutManager.OnSelected {
override fun onItemSelected(position: Int) {
//Cente item
Toast.makeText(this@MainActivity, list[position].text, Toast.LENGTH_LONG).show()
ShowMeIt.text = "Why does cause a Unresolved reference?"
ShowMeIt.text = list[position].text
}})
}
}

activity_main.xml

<RelativeLayout 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=".MainActivity">
<com.jackandphantom.carouselrecyclerview.CarouselRecyclerview
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/recycler"/>
<TextView
android:id="@+id/ShowMeIt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:layout_marginEnd="186dp"
android:layout_marginRight="186dp"
android:layout_marginBottom="106dp"
android:text="Hello" />
</RelativeLayout>

Answer 1

我认为你需要像这样在MainActivity.kt上定义

val ShowMeIt= findViewById<TextView>(R.id.ShowMeIt)