안드로이드 프로그래밍 - 다용도 앱 만들기 8

• 앱의 기능 설명
  • 1. 로그인 기능
  • 2. 메모장
  • 3. 달력
  • 4. 연락처
  • 5. 그림판
  • 6. 미니게임
  • 7. 계산기
  • 8. 스톱워치
  • 9. 가계부

 

• 계산기

계산기

 

• 계산기 xml 코드

<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:background="@color/colorPrimary"
    android:orientation="vertical"
    android:padding="7dp">

    <EditText
        android:id="@+id/number"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:layout_margin="2dp"
        android:background="@android:color/holo_orange_light"
        android:padding="5dp"
        android:textColor="#8E24AA"
        android:textSize="30dp"
        tools:ignore="SpeakableTextPresentCheck" />

    <TableLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1">

        <TableRow
            android:layout_margin="1dp"
            android:layout_weight="1">

            <Button
                android:id="@+id/number1"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="1"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/number2"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="2"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/number3"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="3"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/plus"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="+"
                android:textColor="#FFFFFF"
                android:textSize="25dp" />
        </TableRow>

        <TableRow android:layout_weight="1">

            <Button
                android:id="@+id/number4"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="4"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/number5"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="5"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/number6"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="6"
                android:textColor="#040404"
                android:textSize="25dp" />

            <Button
                android:id="@+id/sub"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="-"
                android:textColor="#FFFFFF"
                android:textSize="25dp" />
        </TableRow>

        <TableRow android:layout_weight="1">

            <Button
                android:id="@+id/number7"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="7"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/number8"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="8"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/number9"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="9"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/mul"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="*"
                android:textColor="#FFFFFF"
                android:textSize="25dp" />
        </TableRow>

        <TableRow android:layout_weight="1">

            <Button
                android:id="@+id/number0"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="0"
                android:textColor="#000000"
                android:textSize="25dp" />

            <Button
                android:id="@+id/ndot"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="."
                android:textColor="#FFFFFF"
                android:textSize="30dp" />

            <Button
                android:id="@+id/clear"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="clear"
                android:textColor="#FFFFFF"
                android:textSize="20dp" />

            <Button
                android:id="@+id/div"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_margin="2dp"
                android:layout_weight="1"
                android:background="#06D1BC"
                android:onClick="onClick"
                android:text="/"
                android:textColor="#FFFFFF"
                android:textSize="25dp" />
        </TableRow>

    </TableLayout>

    <Button
        android:id="@+id/Ok"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:backgroundTint="@android:color/holo_orange_light"
        android:onClick="onClick"
        android:text="확인"
        android:textColor="#8E24AA"
        android:textSize="30dp" />

</LinearLayout>

• TableLayout을 통하여 TableRow를 사용하였다.
• 계산기와 같이 숫자와 연산자들을 입력한 후, 마진을 통하여 콘텐츠 사이의 간격을 두었다.
• 확인 버튼을 통하여 연산이 이루어진 결과를 보이도록 하였다.

 

 

 

• 계산기 java 코드

public class Activity8 extends AppCompatActivity {
    private TextView text;
    private double storedValue;
    private char curOperator;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout8);
        setTitle("Developer 계산기");

        text = findViewById(R.id.number);
    }

    public void onClick(View view) {
        String current = text.getText().toString();

        switch (view.getId()) {
            case R.id.number0:
                text.setText(current + "0");
                break;
            case R.id.number1:
                text.setText(current + "1");
                break;
            case R.id.number2:
                text.setText(current + "2");
                break;
            case R.id.number3:
                text.setText(current + "3");
                break;
            case R.id.number4:
                text.setText(current + "4");
                break;
            case R.id.number5:
                text.setText(current + "5");
                break;
            case R.id.number6:
                text.setText(current + "6");
                break;
            case R.id.number7:
                text.setText(current + "7");
                break;
            case R.id.number8:
                text.setText(current + "8");
                break;
            case R.id.number9:
                text.setText(current + "9");
                break;
            case R.id.ndot:
                text.setText(current + ".");
                break;
            case R.id.plus:
                if (current.equals("")) {
                    Toast.makeText(getApplicationContext(), "숫자를 먼저 입력하세요", Toast.LENGTH_SHORT).show();
                } else {
                    storedValue = Double.parseDouble(current);
                    curOperator = '+';
                    text.setText("");
                    break;
                }
            case R.id.sub:
                if (current.equals("")) {
                    Toast.makeText(getApplicationContext(), "숫자를 먼저 입력하세요", Toast.LENGTH_SHORT).show();
                } else {
                    storedValue = Double.parseDouble(current);
                    curOperator = '-';
                    text.setText("");
                    break;
                }
            case R.id.mul:
                if (current.equals("")) {
                    Toast.makeText(getApplicationContext(), "숫자를 먼저 입력하세요", Toast.LENGTH_SHORT).show();
                } else {
                    storedValue = Double.parseDouble(current);
                    curOperator = '*';
                    text.setText("");
                    break;
                }
            case R.id.div:
                if (current.equals("")) {
                    Toast.makeText(getApplicationContext(), "숫자를 먼저 입력하세요", Toast.LENGTH_SHORT).show();
                } else {
                    storedValue = Double.parseDouble(current);
                    curOperator = '/';
                    text.setText("");
                    break;
                }

            case R.id.clear:
                text.setText("");
                storedValue = 0.0;
                break;

            case R.id.Ok:
                if (current.equals("")) {
                    Toast.makeText(getApplicationContext(), "숫자를 먼저 입력하세요", Toast.LENGTH_SHORT).show();
                } else {
                    double result = 0;
                    double thisValue = Double.parseDouble(text.getText().toString());
                    switch (curOperator) {
                        case '+':
                            result = storedValue + thisValue;
                            break;
                        case '-':
                            result = storedValue - thisValue;
                            break;
                        case '*':
                            result = storedValue * thisValue;
                            break;
                        case '/':
                            result = storedValue / thisValue;
                            break;
                    }
                    text.setText("" + result);
                    storedValue = 0.0;
                    break;
                }
        }
    }
}

 

• switch-case 문을 사용하여, 해당 버튼이 클릭 되었을 때, textView에 입력 되도록 한다.
  • plus,sub,mul,div
  • 버튼 클릭시, 먼저 숫자가 입력 되지 않으면 숫자를 먼저 입력하라는 tosat메시지가 뜨게된다.
  • 값을 입력 받으면 Double로 받아 들여 저장한다.
  • curOperator 연산자 실행
  • clear : 저장된 값을 0.0 으로 리셋
  • ok : switch(curOperator)-case 문을 통해 +,-,*,/ 연산을 실행한다.