Kotlin # 계산기 만들기

🎈 xml로 화면 그리기

우선 화면을 아래와 같이 만든다.

 

 

activity_homework1.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat 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"
    android:orientation="vertical"
    tools:context=".Homework_1">

    <TextView
        android:id="@+id/result"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="@color/black"
        android:gravity="right|bottom"
        android:text="0"
        android:textColor="@color/white"
        android:textSize="60dp" />

    <androidx.appcompat.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/one"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="1"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/two"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="2"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/three"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="3"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/ca"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="CA"
            android:textColor="@color/black"
            android:textSize="60dp" />

    </androidx.appcompat.widget.LinearLayoutCompat>

    <androidx.appcompat.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/four"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="4"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/five"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="5"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/six"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="6"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/plus"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="+"
            android:textColor="@color/black"
            android:textSize="60dp" />

    </androidx.appcompat.widget.LinearLayoutCompat>

    <androidx.appcompat.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/seven"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="7"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/eight"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="8"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/nine"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="9"
            android:textColor="@color/black"
            android:textSize="60dp" />


        <TextView
            android:id="@+id/zero"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:background="@drawable/number_bg"
            android:gravity="center"
            android:text="0"
            android:textColor="@color/black"
            android:textSize="60dp" />

    </androidx.appcompat.widget.LinearLayoutCompat>

    <TextView
        android:id="@+id/equal"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="@drawable/number_bg"
        android:gravity="center"
        android:text="="
        android:textColor="@color/black"
        android:textSize="60dp" />


</androidx.appcompat.widget.LinearLayoutCompat>

 

 

drawable/number_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners android:radius="10dp" />
    <stroke
        android:width="10dp"
        android:color="@color/black" />
    <solid android:color="@color/white" />

</shape>

🎈 Activity로 기능 구현하기

 

Homework_1.kt

package org.techtown.kotlin

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.TextView
import org.w3c.dom.Text

class Homework_1 : AppCompatActivity() {

    lateinit var one: TextView
    lateinit var two: TextView
    lateinit var three: TextView
    lateinit var four: TextView
    lateinit var five: TextView
    lateinit var six: TextView
    lateinit var seven: TextView
    lateinit var eight: TextView
    lateinit var nine: TextView
    lateinit var zero: TextView

    lateinit var ca: TextView
    lateinit var plus: TextView
    lateinit var equal: TextView

    lateinit var result: TextView

    var input: String = ""
    var temp: String = ""


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_homework1)

        findViews()
        setNumberTextViewListenr()

        ca.setOnClickListener {
            input = ""
            temp = ""
            result.text = "0"
        }
        plus.setOnClickListener {
            temp = result.text.toString()
            result.text = ""
            input = ""
        }
        equal.setOnClickListener {
            val finalResult: String = (input.toInt() + temp.toInt()).toString()
            result.text = finalResult
            temp = finalResult
        }

    }

    fun setNumberTextViewListenr() {
        val numberTextViewList: List<TextView> = listOf(
            one, two, three, four, five, six, seven, eight, nine, zero
        )
        val listenr = object : View.OnClickListener {
            override fun onClick(p0: View?) {
                input += (p0 as TextView).text
                result.text = input
            }
        }
        numberTextViewList.forEach { it.setOnClickListener(listenr) }
    }

    fun findViews() {
        one = findViewById(R.id.one)
        two = findViewById(R.id.two)
        three = findViewById(R.id.three)
        four = findViewById(R.id.four)
        five = findViewById(R.id.five)
        six = findViewById(R.id.six)
        seven = findViewById(R.id.seven)
        eight = findViewById(R.id.eight)
        nine = findViewById(R.id.nine)
        zero = findViewById(R.id.zero)
        plus = findViewById(R.id.plus)
        equal = findViewById(R.id.equal)
        ca = findViewById(R.id.ca)
        result = findViewById(R.id.result)
    }


}