Kotlin和xml交互

.kt

package com.easy.hello

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.text.Editable

import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    //lateinit var tv:TextView;
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        //设置左上角标题
        supportActionBar?.setTitle("Kt 测试")

        //文本更改
        //避免types不匹配的做法
        Text1.text = Editable.Factory.getInstance().newEditable("test")
        //简易做法
        Text1.text = "123"
        Text1.setText("123333")

        //Button响应事件
        //短按
        button.setOnClickListener()
        {
            Text1.text = "button被轻点"
        }

        //长按
        button.setOnLongClickListener()
        {
            Text1.text = "长按";true
        }

        //Toast
        
    }

.xml

package com.easy.hello

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.text.Editable

import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    //lateinit var tv:TextView;
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        //设置左上角标题
        supportActionBar?.setTitle("Kt 测试")

        //文本更改
        //避免types不匹配的做法
        Text1.text = Editable.Factory.getInstance().newEditable("test")
        //简易做法
        Text1.text = "123"
        Text1.setText("123333")

        //Button响应事件
        //短按
        button.setOnClickListener()
        {
            Text1.text = "button被轻点"
        }

        //长按
        button.setOnLongClickListener()
        {
            Text1.text = "长按";true
        }

        //Toast
        button2.setOnClickListener()
        {
            Toast.makeText(this,"出",Toast.LENGTH_SHORT).show()}
        }
        
    }

效果