[안드로이드 스튜디오] 간단한 계산기

작동 과정

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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:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">


    <TextView
        android:id="@+id/texttitle1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Number 1" />

    <EditText
        android:id="@+id/editTextText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:text="" />

    <TextView
        android:id="@+id/texttitle2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Number 2" />

    <EditText
        android:id="@+id/editTextText2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:text="" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="+" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="-" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="*" />

    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="/" />

    <TextView
        android:id="@+id/texttitle3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Result" />

    <EditText
        android:id="@+id/editTextText3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:text="" />

</LinearLayout>

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JAVA

package com.example.a03_52;

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

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity {
Button plus,minus,multi,div;
EditText ednum1, ednum2, edresult;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        plus = findViewById(R.id.button1);
        minus = findViewById(R.id.button2);
        multi = findViewById(R.id.button3);
        div = findViewById(R.id.button4);

        ednum1 = findViewById(R.id.editTextText1);
        ednum2 = findViewById(R.id.editTextText2);
        edresult = findViewById(R.id.editTextText3);

        plus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = ednum1.getText().toString();
                String s2 = ednum2.getText().toString();
                int result = Integer.parseInt(s1) + Integer.parseInt(s2);
                edresult.setText("" + result);
            }
        });

        minus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = ednum1.getText().toString();
                String s2 = ednum2.getText().toString();
                int result = Integer.parseInt(s1) - Integer.parseInt(s2);
                edresult.setText("" + result);
            }
        });

        multi.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = ednum1.getText().toString();
                String s2 = ednum2.getText().toString();
                int result = Integer.parseInt(s1) * Integer.parseInt(s2);
                edresult.setText("" + result);
            }
        });

        div.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = ednum1.getText().toString();
                String s2 = ednum2.getText().toString();
                int result = Integer.parseInt(s1) / Integer.parseInt(s2);
                edresult.setText("" + result);
            }
        });
    }
}

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