계산기 만들기

package com.example.mobileapp;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Color;
import android.graphics.Typeface;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {


    EditText edit1, edit2;
    TextView textResult;
    String num1, num2, tmp;
    Integer result;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setTitle("간단한 계산기");


        edit1 = (EditText)findViewById(R.id.Edit1);
        edit2 = (EditText)findViewById(R.id.Edit2);

        textResult = (TextView)findViewById(R.id.TextResult);

    }

    // 덧셈 method
    public void AddClick(View target)
    {

        try{
            num1 = edit1.getText().toString();
            num2 = edit2.getText().toString();
        } catch(NumberFormatException e){
            Toast.makeText(this, "숫자를 입력하세요", Toast.LENGTH_LONG).show();
            return;
        }

        if ((isInteger(num1) & isInteger(num2))==1)
        {
            result = Integer.parseInt(num1) + Integer.parseInt(num2);
            tmp = "계산 결과 : " + result.toString();
            textResult.setText(tmp);
        }
        //else
        //{
        //    Toast.makeText(getApplicationContext(), "No Number", Toast.LENGTH_LONG).show();
        //}

    }

    // 뺄셈 method
    public void SubClick(View target)
    {
        num1 = edit1.getText().toString();
        num2 = edit2.getText().toString();

        if ((isInteger(num1) & isInteger(num2))==1)
        {
            result = Integer.parseInt(num1) - Integer.parseInt(num2);
            tmp = "계산 결과 : " + result.toString();
            textResult.setText(tmp);
        }
        else
        {
            Toast.makeText(getApplicationContext(), "No Number", Toast.LENGTH_LONG).show();
        }
    }

    // 곱셈 method
    public void MultiClick(View target)
    {
        num1 = edit1.getText().toString();
        num2 = edit2.getText().toString();

        if ((isInteger(num1) & isInteger(num2))==1)
        {
            result = Integer.parseInt(num1) * Integer.parseInt(num2);
            tmp = "계산 결과 : " + result.toString();
            textResult.setText(tmp);
        }
        else
        {
            Toast.makeText(getApplicationContext(), "No Number", Toast.LENGTH_LONG).show();
        }
    }

    // 나눗셈 method
    public void DivClick(View target)
    {
        num1 = edit1.getText().toString();
        num2 = edit2.getText().toString();

        if ((isInteger(num1) & isInteger(num2))==1)
        {
            result = Integer.parseInt(num1) / Integer.parseInt(num2);
            tmp = "계산 결과 : " + result.toString();
            textResult.setText(tmp);
        }
        else
        {
            Toast.makeText(getApplicationContext(), "No Number", Toast.LENGTH_LONG).show();
        }
    }

    // integer type method
    static int isInteger(String s) {
        try {
            Integer.parseInt(s);
            return 1;
        } catch(NumberFormatException e) {
            return 0;
        }
    }


}