20250925_android4

실행창

경로 참고

//MainActivity.java

package com.example.project0925_b;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;      // 추가
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    Button btn1;
    TextView txtView1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main01);
        setTitle("hi");

        btn1 = findViewById(R.id.btn1);
        txtView1 = findViewById(R.id.txtView1);

        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                txtView1.setText("Hello World");
                txtView1.setTextColor(Color.parseColor("#FF1111"));
            }
        });  // 괄호 위치 수정
    }
}

<!--main01.xml-->
<!--constraintlayout의 경우 별도로 위치를 지정해줘야함-->
<!--그래서 위치 지정이 필요없는 LinearLayout 사용-->

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="30dp"
    android:orientation="vertical"
    android:gravity="center_horizontal"
>  <!-- weightSum은 총 여백의 비율을 설정합니다 -->

<Button
android:id="@+id/btn1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:text="01"
android:layout_marginBottom="16dp" />

<TextView
android:id="@+id/txtView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:text="02"
android:layout_marginBottom="16dp" />

<Button
android:id="@+id/button3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="03" />

    </LinearLayout>

<resources xmlns:tools="http://schemas.android.com/tools">
    <!-- Base application theme. -->
    <style name="Base.Theme.Project0925_B" parent="Theme.Material3.DayNight">
        <!--.NoActionBar 제거-->
        <!-- Customize your light theme here. -->
        <!-- <item name="colorPrimary">@color/my_light_primary</item> -->
    </style>

    <style name="Theme.Project0925_B" parent="Base.Theme.Project0925_B" />
</resources>

---

simple calculator

실행화면

//MainActivity.java

package com.example.project0925_bb;

import androidx.appcompat.app.AppCompatActivity;

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



public class MainActivity extends AppCompatActivity {

    EditText edit1, edit2;
    Button btnAdd, btnSub, btnMul,btnDiv;
    TextView textResult;
    String num1, num2;
    Integer result;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main01);
        setTitle("simple calculator");

        edit1 = (EditText) findViewById(R.id.Edit1);
        edit2 = (EditText) findViewById(R.id.Edit2);
        btnAdd = (Button) findViewById(R.id.BtnAdd);
        btnSub = (Button) findViewById(R.id.BtnSub);
        btnMul = (Button) findViewById(R.id.BtnMul);
        btnDiv = (Button) findViewById(R.id.BtnDiv);
        textResult = (TextView) findViewById(R.id.TextResult);

        btnAdd.setOnTouchListener(new View.OnTouchListener(){
            @Override
            public boolean onTouch(View org0, MotionEvent arg1){
                num1 = edit1.getText().toString();
                num2 = edit2.getText().toString();
                result=Integer.parseInt(num1)+Integer.parseInt(num2);
                textResult.setText("result : " + result.toString());
                return false;
            }
        });
        btnSub.setOnTouchListener(new View.OnTouchListener(){
            @Override
            public boolean onTouch(View org0, MotionEvent arg1){
                num1 = edit1.getText().toString();
                num2 = edit2.getText().toString();
                result=Integer.parseInt(num1)-Integer.parseInt(num2);
                textResult.setText("result : " + result.toString());
                return false;
            }
        });
        btnMul.setOnTouchListener(new View.OnTouchListener(){
            @Override
            public boolean onTouch(View org0, MotionEvent arg1){
                num1 = edit1.getText().toString();
                num2 = edit2.getText().toString();
                result=Integer.parseInt(num1)*Integer.parseInt(num2);
                textResult.setText("result : " + result.toString());
                return false;
            }
        });
        btnDiv.setOnTouchListener(new View.OnTouchListener(){
            @Override
            public boolean onTouch(View org0, MotionEvent arg1){
                num1 = edit1.getText().toString();
                num2 = edit2.getText().toString();
                result=Integer.parseInt(num1)/Integer.parseInt(num2);
                textResult.setText("result : " + result.toString());
                return false;
            }
        });

    }
}

<!--main01-->

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/Edit1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:hint="enter num1"
        android:textSize="25dp"
        ></EditText>
    <EditText
        android:id="@+id/Edit2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:hint="enter num2"
        android:textSize="25dp"
        ></EditText>
    <Button
        android:id="@+id/BtnAdd"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:textSize="25dp"
        android:text="plus"
        android:visibility="visible"
        ></Button>
    <Button
        android:id="@+id/BtnSub"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:textSize="25dp"
        android:text="minus"
        android:visibility="visible"
        ></Button>
    <Button
        android:id="@+id/BtnMul"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:textSize="25dp"
        android:text="multiple"
        android:visibility="visible"
        ></Button>
    <Button
        android:id="@+id/BtnDiv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:textSize="25dp"
        android:text="devide"
        android:visibility="visible"
        ></Button>
    <TextView
        android:id="@+id/TextResult"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="30dp"
        android:textColor="#FF0000"
        android:layout_margin="10dp"
        android:text="calculate result : "
        ></TextView>
</LinearLayout>