계산기 소스

//java

package com.example.ryan.myapplication_calculator;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

TextView textView1;
TextView textView2;
TextView textView_result;
String num1, num2;
int reNum1,reNum2;
Button btnAdd,btnSub,btnMul,btnDiv;

Button[] numButtons= new Button[10];
Integer[] numBtnIDs ={R.id.button0, R.id.button1,R.id.button2,R.id.button3,R.id.button4,
R.id.button5,R.id.button6,R.id.button7,R.id.button8,R.id.button9};
int result;
int i;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView1 = (TextView) findViewById(R.id.textView1);
        textView2 = (TextView) findViewById(R.id.textView2);
        textView_result = (TextView) findViewById(R.id.textView_rsult);
        Button btnAdd = (Button) findViewById(R.id.btnAdd);
        Button btnSub = (Button) findViewById(R.id.btnSub);
        Button btnMul = (Button) findViewById(R.id.btnMul);
        Button btnDiv = (Button) findViewById(R.id.btnDiv);

        num1 = textView1.getText().toString();
        num2 = textView2.getText().toString();

        reNum1 = Integer.parseInt(num1);
        reNum2 = Integer.parseInt(num2);
        for (i = 0; i < numBtnIDs.length; i++) {
            numButtons[i] = (Button) findViewById(numBtnIDs[i]);
        }
        for (i = 0; i < numBtnIDs.length; i++) {
            final int index;
            index = i;

            numButtons[index].setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if (textView1.isFocused() == true) {
                        num1 = textView1.getText().toString() + numButtons[index].getText().toString();
                        textView1.setText(num1);
                    } else if (textView2.isFocused() == true) {
                        num2 = textView2.getText().toString() + numButtons[index].getText().toString();
                        textView2.setText(num2);
                    } else {
                        Toast.makeText(getApplicationContext(), "먼저 에디트를 선택하세요", Toast.LENGTH_SHORT).show();
                    }
                }
            });
        }
    }


    public void  onButtonClicked(View view){




        switch(view.getId()){
        case R.id.btnAdd:
                result=reNum1+reNum2;
                Toast.makeText(getApplicationContext(), "더하기", Toast.LENGTH_SHORT).show();
                break;
            case R.id.btnSub:
                result=reNum1-reNum2;
                Toast.makeText(getApplicationContext(),"빼기",Toast.LENGTH_SHORT).show();
                break;
            case R.id.btnMul:
                result=reNum1*reNum2;
                Toast.makeText(getApplicationContext(),"곱하기",Toast.LENGTH_SHORT).show();
                break;
            case R.id.btnDiv:
                result=reNum1/reNum2;
                Toast.makeText(getApplicationContext(),"나누기",Toast.LENGTH_SHORT).show();
                break;
        }

    }


}

//xml

<?xml version="1.0" encoding="utf-8"?>
<TableLayout 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="com.example.ryan.myapplication_calculator.MainActivity">

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="54dp">

        <TextView
            android:id="@+id/textView1"
            android:layout_width="match_parent"
            android:layout_height="46dp"
            android:hint="숫자1입력" />
    </TableRow>

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/textView2"
            android:layout_width="match_parent"
            android:layout_height="61dp"
            android:hint="숫자2입력" />
    </TableRow>

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@+id/button0"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="0" />

        <Button
            android:id="@+id/button1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="1" />

        <Button
            android:id="@+id/button2"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="2" />

        <Button
            android:id="@+id/button3"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="3" />

        <Button
            android:id="@+id/button4"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="4" />
    </TableRow>

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@+id/button5"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="5" />

        <Button
            android:id="@+id/button6"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="6" />

        <Button
            android:id="@+id/button7"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="7" />

        <Button
            android:id="@+id/button8"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="8" />

        <Button
            android:id="@+id/button9"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="9" />
    </TableRow>

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@+id/btnAdd"
            android:layout_width="385dp"
            android:layout_height="match_parent"
            android:onClick="onButtonClicked"
            android:text="더하기" />
    </TableRow>

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <Button
            android:id="@+id/btnSub"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="onButtonClicked"
            android:text="빼기" />

    </TableRow>

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@+id/btnMul"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="onButtonClicked"
            android:text="곱하기" />
    </TableRow>

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <Button
            android:id="@+id/btnDiv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="onButtonClicked"
            android:text="나누기" />
    </TableRow>

    <TableRow
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/textView_rsult"
            android:layout_width="wrap_content"
            android:layout_height="71dp"
            android:hint=" 계산결과:" />
    </TableRow>
</TableLayout>