[ Java ] 계산기 만들기

화면 만들기

 

 

 

 

 

 

코드 작성

 - MainActivity.java

package com.example.mainactivity;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import java.net.InterfaceAddress;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    // 덧셈
    public void addClick(View v) {
        EditText number1 = (EditText) findViewById(R.id.number1);
        EditText number2 = (EditText) findViewById(R.id.number2);
        TextView result = (TextView) findViewById(R.id.result);
        int n1 = Integer.parseInt(number1.getText().toString());
        int n2 = Integer.parseInt(number2.getText().toString());
        result.setText(Integer.toString(n1 + n2));
    }

    // 뺄셈
    public void subtractClick(View v) {
        EditText number1 = (EditText) findViewById(R.id.number1);
        EditText number2 = (EditText) findViewById(R.id.number2);
        TextView result = (TextView) findViewById(R.id.result);
        int n1 = Integer.parseInt(number1.getText().toString());
        int n2 = Integer.parseInt(number2.getText().toString());
        result.setText(Integer.toString(n1 - n2));
    }

    // 곱셈
    public void multipleClick(View v) {
        EditText number1 = (EditText) findViewById(R.id.number1);
        EditText number2 = (EditText) findViewById(R.id.number2);
        TextView result = (TextView) findViewById(R.id.result);
        int n1 = Integer.parseInt(number1.getText().toString());
        int n2 = Integer.parseInt(number2.getText().toString());
        result.setText(Integer.toString(n1 * n2));
    }

    // 나눗셈
    public void divideClick(View v) {
        EditText number1 = (EditText) findViewById(R.id.number1);
        EditText number2 = (EditText) findViewById(R.id.number2);
        TextView result = (TextView) findViewById(R.id.result);
        int n1 = Integer.parseInt(number1.getText().toString());
        int n2 = Integer.parseInt(number2.getText().toString());
        result.setText(Integer.toString(n1 / n2));
    }
}

 

 

 - activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    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"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/number1"
        android:layout_width="340dp"
        android:layout_height="54dp"
        android:layout_marginStart="24dp"
        android:layout_marginTop="52dp"
        android:ems="10"
        android:hint="첫 번째 숫자"
        android:inputType="textPersonName"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/number2"
        android:layout_width="340dp"
        android:layout_height="48dp"
        android:layout_marginStart="24dp"
        android:layout_marginTop="116dp"
        android:ems="10"
        android:hint="두 번째 숫자"
        android:inputType="textPersonName"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/addButton"
        android:layout_width="90dp"
        android:layout_height="48dp"
        android:layout_marginStart="4dp"
        android:layout_marginTop="184dp"
        android:onClick="addClick"
        android:text="더하기"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/subtractButton"
        android:layout_width="90dp"
        android:layout_height="48dp"
        android:layout_marginStart="100dp"
        android:layout_marginTop="184dp"
        android:onClick="subtractClick"
        android:text="빼기"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/divideButton"
        android:layout_width="90dp"
        android:layout_height="48dp"
        android:layout_marginStart="296dp"
        android:layout_marginTop="184dp"
        android:onClick="divideClick"
        android:text="나누기"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/multipleButton"
        android:layout_width="90dp"
        android:layout_height="48dp"
        android:layout_marginStart="198dp"
        android:layout_marginTop="184dp"
        android:onClick="multipleClick"
        android:text="곱하기"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/result"
        android:layout_width="335dp"
        android:layout_height="54dp"
        android:layout_marginStart="28dp"
        android:layout_marginTop="252dp"
        android:textAppearance="@style/TextAppearance.AppCompat.Display1"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

 

 

 

 

 

결과물

 

 

 

+++ 안드로이드 스튜디오 화면 구성 겹치는 경우

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