labs-mobile-applications/app/src/main/java/com/example/myapplication/MainActivity.kt

package com.example.myapplication

import android.os.Bundle
import android.widget.Button
import android.widget.EditText
import android.widget.TextView
import android.widget.Toast
import androidx.activity.ComponentActivity
import java.io.File

class MainActivity : ComponentActivity() {

    private lateinit var etInput: EditText
    private lateinit var btnSave: Button
    private lateinit var btnLoad: Button
    private lateinit var tvResult: TextView

    private val fileName = "myfile.txt"

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

        etInput = findViewById(R.id.etInput)
        btnSave = findViewById(R.id.btnSave)
        btnLoad = findViewById(R.id.btnLoad)
        tvResult = findViewById(R.id.tvResult)

        btnSave.setOnClickListener { saveToFile() }
        btnLoad.setOnClickListener { loadFromFile() }
    }

    private fun saveToFile() {
        val text = etInput.text.toString()
        if (text.isEmpty()) {
            Toast.makeText(this, "Введите текст", Toast.LENGTH_SHORT).show()
            return
        }

        val file = File(filesDir, fileName)
        file.writeText(text)

        Toast.makeText(this, "Файл сохранён", Toast.LENGTH_SHORT).show()
    }

    private fun loadFromFile() {
        val file = File(filesDir, fileName)
        if (file.exists()) {
            val content = file.readText()
            tvResult.text = "Содержимое файла: $content"
        } else {
            tvResult.text = "Файл не найден"
        }
    }
}