안드로이드 계산기 어플 만들기 - andeuloideu gyesangi eopeul mandeulgi

프로그래밍

안드로이드 계산기 앱 제작 및 배포

2021. 7. 18. 14:15

Image : Marshmallow, API Level 23, Android 6.0, ABI x86
AVD Hardware : Nexus 4(768x1280, xhdpi)
language : java

res/layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
	    android:weightSum="100"
	    tools:context=".MainActivity">
 	
	    <LinearLayout
	        android:layout_width="match_parent"
	        android:layout_height="0dp"
	        android:layout_weight="20"
	        android:orientation="vertical">
	
	
	        <TextView
	            android:id="@+id/result_text"
	            android:layout_width="match_parent"
	            android:layout_height="match_parent"
	            android:layout_margin="10dp"
 	            android:gravity="center_vertical|right"
	            android:padding="5dp"
	            android:text="0"
	            android:textSize="50sp"
	            android:textColor="#666666"/>
 	
	    </LinearLayout>
 	
 	    <TextView
 	        android:layout_width="match_parent"
 	        android:layout_height="1dp"
 	        android:background="#000000" />
 	
 	    <LinearLayout
 	        android:layout_width="match_parent"
 	        android:layout_height="0dp"
 	        android:layout_weight="80"
 	        android:orientation="vertical"
 	        android:padding="10dp"
 	        android:weightSum="100">
 	
 	        <LinearLayout
 	            android:layout_width="match_parent"
 	            android:layout_height="0dp"
 	            android:layout_weight="20"
 	            android:orientation="horizontal"
 	            android:weightSum="100">
 	
 	            <Button
 	                android:id="@+id/all_clear_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="buttonClick"
 	                android:text="AC"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/clear_entry_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="buttonClick"
 	                android:text="CE"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/back_space_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="buttonClick"
 	                android:text="BS"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/division_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:backgroundTint="#929292"
 	                android:onClick="operatorClick"
 	                android:text="/"
 	                android:textSize="30sp" />
 	
 	        </LinearLayout>
 	
 	        <LinearLayout
 	            android:layout_width="match_parent"
 	            android:layout_height="0dp"
 	            android:layout_weight="20"
 	            android:orientation="horizontal"
 	            android:weightSum="100">
 	
 	            <Button
 	                android:id="@+id/num7_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="7"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/num8_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="8"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/num9_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="9"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/multi_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:backgroundTint="#929292"
 	                android:onClick="operatorClick"
 	                android:text="*"
 	                android:textSize="30sp" />
 	
 	        </LinearLayout>
 	
 	        <LinearLayout
 	            android:layout_width="match_parent"
 	            android:layout_height="0dp"
 	            android:layout_weight="20"
 	            android:orientation="horizontal"
 	            android:weightSum="100">
 	
 	            <Button
 	                android:id="@+id/num4_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="4"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/num5_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="5"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/num6_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="6"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/sub_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:backgroundTint="#929292"
 	                android:onClick="operatorClick"
 	                android:text="-"
 	                android:textSize="30sp" />
 	
 	        </LinearLayout>
 	
 	        <LinearLayout
 	            android:layout_width="match_parent"
 	            android:layout_height="0dp"
 	            android:layout_weight="20"
 	            android:orientation="horizontal"
 	            android:weightSum="100">
 	
 	            <Button
 	                android:id="@+id/num1_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="1"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/num2_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="2"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/num3_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="numButtonClick"
 	                android:text="3"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/add_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:backgroundTint="#929292"
 	                android:onClick="operatorClick"
 	                android:text="+"
 	                android:textSize="30sp" />
 	
 	        </LinearLayout>
 	
 	        <LinearLayout
 	            android:layout_width="match_parent"
 	            android:layout_height="0dp"
 	            android:layout_weight="20"
 	            android:orientation="horizontal"
 	            android:weightSum="100">
 	
 	            <Button
 	                android:id="@+id/num0_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="75"
 	                android:onClick="numButtonClick"
 	                android:text="0"
 	                android:textSize="30sp" />
 	
 	            <Button
 	                android:id="@+id/res_but"
 	                android:layout_width="0dp"
 	                android:layout_height="match_parent"
 	                android:layout_weight="25"
 	                android:onClick="operatorClick"
 	                android:text="="
 	                android:textSize="30sp"
 	                android:background="#929292"/>
 	
 	        </LinearLayout>
 	
 	
 	    </LinearLayout>
 	
 	</LinearLayout>

MainActivity.java

package com.cac.calc;
 	
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
 	
public class MainActivity extends AppCompatActivity {
 	
    boolean isFirstInput = true; // 입력 값이 처음 입력되는가를 체크
    int resultNumber = 0; // 계산 값 저장
    char operator = '+'; // 연산자 저장
 	
    final String CLEAR_INPUT_TEXT = "0";
 	
    TextView resultText;
 	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        resultText = findViewById(R.id.result_text);
    }
 	
    // AC, CE, BS 클릭
    public void buttonClick(View view) {

        switch ( view.getId() )
        {
            case R.id.all_clear_but:
                resultNumber = 0;
                operator = '+';
                setClearText(CLEAR_INPUT_TEXT);
                break;

            case R.id.clear_entry_but:
                setClearText(CLEAR_INPUT_TEXT);
                break;

            case R.id.back_space_but:
                if (resultText.getText().toString().length() > 1 )
                {
                    String getResultText = resultText.getText().toString();
                    String subString = getResultText.substring(0,getResultText.length()-1);
                    resultText.setText(subString);
                } else {
                    resultText.setTextColor(0xFF666666);
                    resultText.setText(CLEAR_INPUT_TEXT);
                    isFirstInput = true;
                }
                break;

            default:
               break;

        }
    }

    // 입력된 숫자를 초기화
    public void setClearText(String clearText)
    {
        isFirstInput = true;
        resultText.setTextColor(0xFF666666);
        resultText.setText(clearText);
    }

    // 0~9 버튼 클릭
    public void numButtonClick(View view)
    {
        Button getButton = findViewById(view.getId());

        if(isFirstInput){
           resultText.setTextColor(0xFF000000);
           resultText.setText(getButton.getText().toString());
 	       isFirstInput = false;
 	      } else {
 	    if (resultText.getText().toString().equals("0"))
 	          {
 	              Toast.makeText(getApplicationContext(), "초기 입력값이 0입니다.",Toast.LENGTH_LONG).show();
 	              setClearText(CLEAR_INPUT_TEXT);
 	              return;
 	          }
 	             resultText.append(getButton.getText().toString());
 	     }
 	 }
 	
 	
 	
 	  // 사칙연산 값을 반환
 	  public int intCal(int result, int lastNum, char operator)
 	  {
 	      if ( operator == '+'){
 	          result += lastNum;
 	      } else if ( operator == '-') {
 	          result -= lastNum;
 	      } else if ( operator == '/') {
 	          result /= lastNum;
 	      } else if ( operator == '*') {
 	          result *= lastNum;
 	      }
 	      return result;
 	  }
 	
    // 연산자 클릭
    public void operatorClick(View view)
    {
        Button getButton = findViewById(view.getId());

        if(view.getId() == R.id.res_but) {
            if(isFirstInput){
                resultNumber = 0;
                operator = '+';
                setClearText(CLEAR_INPUT_TEXT);
                // = 두번 이상 누를 때 처리
            } else {
                resultNumber = intCal(resultNumber, Integer.parseInt(resultText.getText().toString()), operator);
                resultText.setText(String.valueOf(resultNumber));
                isFirstInput = true;
            }

        } else {

            if(isFirstInput){
                operator = getButton.getText().toString().charAt(0);
            } else {
                int lastNum = Integer.parseInt(resultText.getText().toString());
                resultNumber = intCal(resultNumber, lastNum, operator);
                operator = getButton.getText().toString().charAt(0);
                resultText.setText(String.valueOf(resultNumber));
                isFirstInput = true;
            }
        }
    }
}

app/res/values/strings.xml

 	<resources>
 	    <string name="app_name">계산기</string>
 	</resources>

안드로이드 APK 배포

Build > Generate Signed APK > APK > Create new...
> New Key Store 항목 입력 > release 선택, V1-V2 모두 체크 > 프로젝트 폴더(app/release) apk 배포 완료

Playstore 배포

구글플레이 스토어 콘솔 이동 https://play.google.com/console/signup > 애플리케이션 만들기 >
새 개발자 계정 만들기(25$ 결제필요) > (모든 앱 > 첫 번째 앱 만들기) >
(대시보드 > 스토어 등록정보 설정 > 할 일 보기에 나온 항목 모두 설정) > (대시보드 > Google Play에 앱 게시) >
프로덕션 트랙으로 출시 시작

* apk파일 업로드 시 com.example이 제한된 상태이므로 다른 패키지 이름을 사용해야 합니다. 해결 방법
안드로이드 스튜디오 > 패키지명 바꿀 폴더 오른쪽 상단의 톱니바퀴 클릭 > Compact Middle Packages 선택 해제
> app/src/main/java/"example" 패키지 우클릭 후 Refector, Rename > Rename Packages > 변경할 패키지명 >
build.gradle 스크립트에서 applicationId를 변경한 패키지명으로 수정 > (Build > Build Bundle(s) / Build APK(s) > Build APK(s)) >
안드로이드 APK 배포

계산기 앱 제작 강의 : 
https://www.youtube.com/watch?v=cZXMzTL17es&list=PLMocbRXgGcjZwmzqb0meFSeH9uh_FC-dM&index=2

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