작동 과정
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>
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);
}
});
}
}