작심삼일ing

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_margin="20dp"
    android:layout_height="match_parent"
    tools:context="examples.com.myapplication2.Main2Activity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="사과의 가격은?"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="숫자로 입력"
        android:id="@+id/editText"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="사과의 개수는?"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="숫자로 입력"
        android:id="@+id/editText2"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/btn"
        android:text="총 금액 계산하기"/>
</LinearLayout>

package examples.com.myapplication2;

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

public class Main2Activity extends AppCompatActivity {
    EditText e1, e2;
    Button b1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        setTitle("사과가격 계산기");
        init();
    }

    void init(){
        e1 = (EditText)findViewById(R.id.editText);
        e2 = (EditText)findViewById(R.id.editText2);
        b1 = (Button)findViewById(R.id.btn);

        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String price = e1.getText().toString();
                String count = e2.getText().toString();
                int result = Integer.parseInt(price)*Integer.parseInt(count);

                Toast.makeText(getApplicationContext(),"사과의 가격은 " + result, Toast.LENGTH_SHORT).show();
            }
        });
    }

} 

<?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:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_margin="20dp"
    android:layout_height="match_parent"
    tools:context="examples.com.myapplication2.Main3Activity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="태어난 년도를 입력하세요."/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="숫자를 입력하세요."
        android:id="@+id/age_edit"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="나이계산"
        android:id="@+id/age_btn"/>
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="나이를 입력하세요."/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="숫자를 입력하세요."
        android:id="@+id/age_edit2"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/age_btn2"
        android:text="태어난 해 계산"/>

</LinearLayout> 

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:layout_margin="20dp"
    tools:context="examples.com.myapplication2.Main5Activity">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:weightSum="7"
        android:orientation="horizontal">


        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="5"
            android:text="피자(15000원)" />

        <EditText
            android:id="@+id/h3_edit"
            android:layout_weight="2"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:hint="개수 입력"/>

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:weightSum="7"
        android:orientation="horizontal">


        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="5"
            android:text="스파게티(13000원)" />

        <EditText
            android:id="@+id/h3_edit2"
            android:layout_weight="2"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:hint="개수 입력"/>

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:weightSum="7"
        android:orientation="horizontal">


        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="5"
            android:text="샐러드(9000원)" />

        <EditText
            android:id="@+id/h3_edit3"
            android:layout_weight="2"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:hint="개수 입력"/>

    </LinearLayout>

    <CheckBox
        android:id="@+id/checkBox"
        android:layout_width="match_parent"
        android:textStyle="bold"
        android:layout_height="wrap_content"
        android:text="멤버쉽 카드 있음(10%할인)" />

    <Button
        android:id="@+id/h3_btn"
        android:layout_width="match_parent"
        android:textStyle="bold"
        android:layout_height="wrap_content"
        android:text="금액 계산하기" />

    <LinearLayout
        android:layout_width="match_parent"
        android:orientation="horizontal"
        android:weightSum="7"
        android:layout_height="wrap_content">
        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="5"
            android:text="주문개수"/>

        <TextView
            android:layout_width="0dp"
            android:layout_weight="2"
            android:layout_height="wrap_content"
            android:id="@+id/h3_text"
            android:text="0개" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:orientation="horizontal"
        android:weightSum="7"
        android:layout_height="wrap_content">
        <TextView
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="5"
            android:text="주문개수"/>

        <TextView
            android:layout_width="0dp"
            android:id="@+id/h3_text2"
            android:layout_weight="2"
            android:layout_height="wrap_content"
            android:text="0개" />
    </LinearLayout>

</LinearLayout> 

package examples.com.myapplication2;

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


public class Main5Activity extends AppCompatActivity {
    EditText e1, e2, e3;
    Button btn;
    CheckBox checkBox;
    TextView text1,text2;
    int PIZZA = 15000, SPAGHETTI = 13000, SALAD = 9000;
    double DISCOUNT = 0.9;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main5);
        setTitle("레스토랑 주문");

        init();

    }



    void init() {
        e1 = (EditText) findViewById(R.id.h3_edit);
        e2 = (EditText) findViewById(R.id.h3_edit2);
        e3 = (EditText) findViewById(R.id.h3_edit3);

        btn = (Button) findViewById(R.id.h3_btn);

        checkBox = (CheckBox) findViewById(R.id.checkBox);

        text1 = (TextView) findViewById(R.id.h3_text);
        text2 = (TextView) findViewById(R.id.h3_text2);

        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                int t1 = Integer.parseInt(e1.getText().toString());
                int t2 = Integer.parseInt(e2.getText().toString());
                int t3 = Integer.parseInt(e3.getText().toString());

                int result1 = t1 + t2 + t3;
                int result2 = t1 * PIZZA + t2 * SPAGHETTI + t3 * SALAD;


                if (checkBox.isChecked()) {
                    result2 = (int) (result2 * DISCOUNT);
                }

                text1.setText(result1+"개");
                text2.setText(result2+"원");
            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_margin="20dp"
    android:layout_height="match_parent"
    tools:context="examples.com.myapplication2.Main6Activity">

    <LinearLayout
        android:orientation="horizontal"
        android:weightSum="10"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <TextView
            android:layout_width="0dp"
            android:layout_weight="1.35"
            android:layout_height="wrap_content"
            android:text="숫자 1 "/>
        <EditText
            android:layout_width="0dp"
            android:layout_weight="8.65"
            android:layout_height="wrap_content"
            android:hint="정수 입력"
            android:id="@+id/h4_edit"/>
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:weightSum="10"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <TextView
            android:layout_width="0dp"
            android:layout_weight="1.35"
            android:layout_height="wrap_content"
            android:text="숫자 2 "/>
        <EditText
            android:layout_width="0dp"
            android:layout_weight="8.65"
            android:layout_height="wrap_content"
            android:hint="정수 입력"
            android:id="@+id/h4_edit2"/>
    </LinearLayout>

    <Button
        android:id="@+id/h4_btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="더하기" />

    <Button
        android:id="@+id/h4_btn2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="빼기" />

    <Button
        android:id="@+id/h4_btn3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="곱하기" />

    <Button
        android:id="@+id/h4_btn4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="나누기" />

</LinearLayout> 

package examples.com.myapplication2;

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

public class Main6Activity extends AppCompatActivity {
    EditText e1, e2;
    Button btn1, btn2, btn3, btn4;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main6);
        setTitle("계산기");

        init();
    }

    void init(){
        e1 = (EditText)findViewById(R.id.h4_edit);
        e2 = (EditText)findViewById(R.id.h4_edit2);

        btn1 = (Button)findViewById(R.id.h4_btn);
        btn2 = (Button)findViewById(R.id.h4_btn2);
        btn3 = (Button)findViewById(R.id.h4_btn3);
        btn4 = (Button)findViewById(R.id.h4_btn4);

        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = e1.getText().toString();
                String s2 = e2.getText().toString();

                if(emptyCheck(s1, s2));
                else{
                    int result = Integer.parseInt(s1)+Integer.parseInt(s2);
                    Toast.makeText(getApplicationContext(), "더하기 계산 결과는 "+result+"입니다",Toast.LENGTH_SHORT).show();
                }
            }
        });

        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = e1.getText().toString();
                String s2 = e2.getText().toString();

                if(emptyCheck(s1, s2));
                else{
                    int result = Integer.parseInt(s1)-Integer.parseInt(s2);
                    Toast.makeText(getApplicationContext(), "더하기 빼기 결과는 "+result+"입니다",Toast.LENGTH_SHORT).show();
                }

            }
        });

        btn3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = e1.getText().toString();
                String s2 = e2.getText().toString();

                if(emptyCheck(s1,s2));
                else{
                    int result = Integer.parseInt(s1)*Integer.parseInt(s2);
                    Toast.makeText(getApplicationContext(), "곱하기 계산 결과는 "+result+"입니다",Toast.LENGTH_SHORT).show();
                }

            }
        });

        btn4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String s1 = e1.getText().toString();
                String s2 = e2.getText().toString();

                if(emptyCheck(s1,s2));
                else{
                    double result = (double)Integer.parseInt(s1)/Integer.parseInt(s2);
                    Toast.makeText(getApplicationContext(), "나누기 계산 결과는 "+result+"입니다",Toast.LENGTH_SHORT).show();
                }

            }
        });

    }
    boolean isEmpty(String s){
        return s == null || s.equals("");
    }

    boolean emptyCheck(String s1, String s2){
        if(isEmpty(s1)){
            Toast.makeText(getApplicationContext(),"값을 입력하세요.",Toast.LENGTH_SHORT).show();
            e1.requestFocus();
            return true;
        }else if(isEmpty(s2)){
            Toast.makeText(getApplicationContext(),"값을 입력하세요.",Toast.LENGTH_SHORT).show();
            e2.requestFocus();
            return true;
        }
        return false;
    }

} 

<?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:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_margin="20dp"
    android:layout_height="match_parent"
    tools:context="examples.com.myapplication2.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="나의 첫번째 App"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="사과가격 계산" />

    <Button
        android:id="@+id/button2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="나이계산기" />

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

    <Button
        android:id="@+id/button4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="레스토랑 주문" />

    <Button
        android:id="@+id/button5"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="계산기" />

</LinearLayout> 

package examples.com.myapplication2;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {
    Button b1, b2, b3, b4, b5;
    Intent intent;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();

    }

    void init(){
        b1 = (Button)findViewById(R.id.button);
        b2 = (Button)findViewById(R.id.button2);
        b3 = (Button)findViewById(R.id.button3);
        b4 = (Button)findViewById(R.id.button4);
        b5 = (Button)findViewById(R.id.button5);

        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                intent = new Intent(MainActivity.this, Main2Activity.class);
                startActivity(intent);
            }
        });

        b2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                intent = new Intent(MainActivity.this, Main3Activity.class);
                startActivity(intent);
            }
        });

        b3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                intent = new Intent(MainActivity.this, Main4Activity.class);
                startActivity(intent);
            }
        });

        b4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                intent = new Intent(MainActivity.this, Main5Activity.class);
                startActivity(intent);
            }
        });

        b5.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                intent = new Intent(MainActivity.this, Main6Activity.class);
                startActivity(intent);
            }
        });
    }
}