[코틀린을 활용한 안드로이드 프로그래밍] 8장 직접 풀어보기 8-1

[Gradle 설정]

1

id 'kotlin-android-extensions'

cs

<MainActivity>

package com.cookandroid.project8_1
 
import android.content.Context
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*
import java.lang.Exception
import java.nio.charset.Charset
import java.util.*
 
class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        title = "간단 일기장"
 
        var cal = Calendar.getInstance()
        var cYear = cal.get(Calendar.YEAR)
        var cMonth = cal.get(Calendar.MONTH)
        var cDay = cal.get(Calendar.DAY_OF_MONTH)
        var fileName  = "${cYear}_${cMonth}_${cDay}.txt"
        var str = readDiary(fileName)
        edtDiary.setText(str)
        btnWrite.isEnabled = true
 
 
 
        datePicker1.init(cYear, cMonth, cDay){view, year, monthOfYear, dayOfMonth ->
            fileName = year.toString() + "_" + monthOfYear.toShort() + "_" + dayOfMonth.toString() + ".txt"
            var str = readDiary(fileName!!)
            edtDiary.setText(str)
            btnWrite.isEnabled = true
        }
 
        btnWrite.setOnClickListener {
            var outFs = openFileOutput(fileName, Context.MODE_PRIVATE)
            var str = edtDiary.text.toString()
            outFs.write(str.toByteArray())
            outFs.close()
            Toast.makeText(applicationContext, "${fileName} 이 저장됨", Toast.LENGTH_SHORT).show()
        }
 
    }
 
    fun readDiary(fName : String) : String?{
        var diaryStr : String? = null
        try{
            var inFs = openFileInput(fName)
            var txt = ByteArray(inFs.available())
            inFs.read(txt)
            inFs.close()
            diaryStr = txt.toString(Charsets.UTF_8).trim()
            btnWrite.text = "수정하기"
 
        }catch(e : Exception){
            edtDiary.hint = "일기 없음"
            btnWrite.text = "새로 저장"
        }
        return diaryStr
 
    }
}

<activity_main.xml>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
 
    <DatePicker
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:datePickerMode="spinner"
        android:calendarViewShown="false"
        android:id="@+id/datePicker1"/>
    <EditText
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:lines="8"
        android:id="@+id/edtDiary"
        android:background="#00ff00"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="새로 저장"
        android:layout_margin="5dp"
        android:enabled="false"
        android:id="@+id/btnWrite"/>
 
</LinearLayout>