​使用Kotlin和Android Studio开发Android应用的详细教程

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/helloTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello, Kotlin!"
        android:textSize="24sp"
        android:layout_centerInParent="true"/>
</RelativeLayout>

import android.os.Bundle
import android.view.View
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    private lateinit var helloTextView: TextView

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

        helloTextView = findViewById(R.id.helloTextView)
    }

    fun onButtonClick(view: View) {
        helloTextView.text = "Hello, Kotlin and Android!"
    }
}