1. Activity를 이용한 계산기

MainActivity.java

 

package com.ktds.myactivityforresult;
 
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
 
 
public class MainActivity extends ActionBarActivity {
 
    private EditText one;
    private EditText two;
    private Button plus;
    private Button minus;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        one = (EditText) findViewById(R.id.one);
        two = (EditText) findViewById(R.id.two);
        plus = (Button) findViewById(R.id.plus);
        minus = (Button) findViewById(R.id.minus);
 
        plus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String oneValue = one.getText().toString();
                String twoValue = two.getText().toString();
 
                Intent intent = new Intent(MainActivity.this, calcActivity.class);
                intent.putExtra("one",oneValue);
                intent.putExtra("two",twoValue);
                intent.putExtra("requestCode",1001);
                startActivityForResult(intent, 1001);
            }
        });
 
        minus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String oneValue = one.getText().toString();
                String twoValue = two.getText().toString();
 
                Intent intent = new Intent(MainActivity.this, calcActivity.class);
                intent.putExtra("one",oneValue);
                intent.putExtra("two",twoValue);
                intent.putExtra("requestCode",1002);
                startActivityForResult(intent, 1002);
            }
        });
    }
    /**
     * Activity로 부터 응답을 받으면 실행되는 메소드
     * @param requestCode : 요청코드
     * @param resultCode : 결과코드
     * @param data : resultIntent
     */
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
 
        if(requestCode==1001 || requestCode==1002){
            if(resultCode==RESULT_OK){
                String result = data.getIntExtra("result",0)+"";
                Toast.makeText(this, result, Toast.LENGTH_LONG).show();
            }
        }
    }
}
 

 

calcActivity.java

 

package com.ktds.myactivityforresult;
 
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.Button;
 
 
public class calcActivity extends ActionBarActivity {
 
    private Button btnCalc;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_calc);
 
        btnCalc = (Button) findViewById(R.id.btnCalc);
 
        Intent intent = getIntent();
 
        final String one = intent.getStringExtra("one");
        final String two = intent.getStringExtra("two");
        final int requestCode = intent.getIntExtra("requestCode",0);
 
        btnCalc.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
 
                int result = 0;
                if(requestCode==1001) {
                    result = Integer.parseInt(one) + Integer.parseInt(two);
                }
                else if(requestCode==1002){
                    result = Integer.parseInt(one) - Integer.parseInt(two);
                }
 
                Intent resultIntent = new Intent();
                resultIntent.putExtra("result", result);
 
                // setResult(응답코드, 정보를 전달 할 intent)
                setResult(RESULT_OK, resultIntent);
                finish();
            }
        });
    }
 
 
}
 

 

 

activity_calc.xml

 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="com.ktds.myactivityforresult.calcActivity">
 
    <Button
        android:id="@+id/btnCalc"
        android:text="계산하기"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
 
</RelativeLayout>
 

 

 

activity_main.xml

 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">
 
    <EditText
        android:id="@+id/one"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
 
    <Button
        android:id="@+id/plus"
        android:text="더하기"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Button
        android:id="@+id/minus"
        android:text="빼기"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
 
    <EditText
        android:id="@+id/two"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
 
</LinearLayout>