배열과 테이블 위젯 이용한 계산기, 숫자버튼 예제

1. activity_main.xml

<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/tableLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnCount="5"
    android:orientation="vertical"
    android:rowCount="9">

    <EditText
        android:id="@+id/Edit1"
        android:layout_columnSpan="5"
        android:layout_gravity="fill_horizontal"
        android:hint="숫자1 입력" />

    <EditText
        android:id="@+id/Edit2"
        android:layout_columnSpan="5"
        android:layout_gravity="fill_horizontal"
        android:hint="숫자2 입력" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <Button
            android:id="@+id/BtnNum0"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="0" />

        <Button
            android:id="@+id/BtnNum1"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="1" />

        <Button
            android:id="@+id/BtnNum2"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="2" />

        <Button
            android:id="@+id/BtnNum3"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="3" />

        <Button
            android:id="@+id/BtnNum4"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="4" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <Button
            android:id="@+id/BtnNum5"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="5" />

        <Button
            android:id="@+id/BtnNum6"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="6" />

        <Button
            android:id="@+id/BtnNum7"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="7" />

        <Button
            android:id="@+id/BtnNum8"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="8" />

        <Button
            android:id="@+id/BtnNum9"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="9" />
    </LinearLayout>
    <Button
        android:id="@+id/BtnAdd"
        android:layout_column="0"
        android:layout_columnSpan="5"
        android:layout_gravity="fill_horizontal"
        android:layout_margin="5dp"
        android:layout_row="4"
        android:text="더하기" />

    <Button
        android:id="@+id/BtnSub"
        android:layout_column="0"
        android:layout_columnSpan="5"
        android:layout_gravity="fill_horizontal"
        android:layout_margin="5dp"
        android:layout_row="5"
        android:text="빼기" />

    <Button
        android:id="@+id/BtnMul"
        android:layout_column="0"
        android:layout_columnSpan="5"
        android:layout_gravity="fill_horizontal"
        android:layout_margin="5dp"
        android:layout_row="6"
        android:text="곱하기" />

    <Button
        android:id="@+id/BtnDiv"
        android:layout_column="0"
        android:layout_columnSpan="5"
        android:layout_gravity="fill_horizontal"
        android:layout_margin="5dp"
        android:layout_row="7"
        android:text="나누기" />

    <TextView
        android:id="@+id/TextResult"
        android:layout_column="0"
        android:layout_columnSpan="5"
        android:layout_gravity="fill_horizontal"
        android:layout_margin="5dp"
        android:layout_row="8"
        android:text="계산 결과 : "
        android:textColor="#FF0000"
        android:textSize="20dp" />

</GridLayout>

2. MainActivity.java

    EditText edit1, edit2;
    Button btnAdd, btnSub, btnMul, btnDiv;
    TextView textResult;
    String num1, num2;
    Integer result;

    // 10개 숫자 버튼 배열
    Button[] numButtons = new Button[10];
    // 10개 숫자 버튼의 id 값 배열
    Integer[] numBtnIDs = { R.id.BtnNum0, R.id.BtnNum1, R.id.BtnNum2,
            R.id.BtnNum3, R.id.BtnNum4, R.id.BtnNum5, R.id.BtnNum6,
            R.id.BtnNum7, R.id.BtnNum8, R.id.BtnNum9 };
    int i; // 증가값 용도

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        setTitle("그리드레이아웃 계산기");

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

        btnAdd = (Button) findViewById(R.id.BtnAdd);
        btnSub = (Button) findViewById(R.id.BtnSub);
        btnMul = (Button) findViewById(R.id.BtnMul);
        btnDiv = (Button) findViewById(R.id.BtnDiv);

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

        btnAdd.setOnTouchListener(new View.OnTouchListener() {
            public boolean onTouch(View arg0, MotionEvent arg1) {
                num1 = edit1.getText().toString();
                num2 = edit2.getText().toString();
                result = Integer.parseInt(num1) + Integer.parseInt(num2);
                textResult.setText("계산 결과 : " + result.toString());
                return false;
            }
        });

        btnSub.setOnTouchListener(new View.OnTouchListener() {
            public boolean onTouch(View arg0, MotionEvent arg1) {
                num1 = edit1.getText().toString();
                num2 = edit2.getText().toString();
                result = Integer.parseInt(num1) - Integer.parseInt(num2);
                textResult.setText("계산 결과 : " + result.toString());
                return false;
            }
        });

        btnMul.setOnTouchListener(new View.OnTouchListener() {
            public boolean onTouch(View arg0, MotionEvent arg1) {
                num1 = edit1.getText().toString();
                num2 = edit2.getText().toString();
                result = Integer.parseInt(num1) * Integer.parseInt(num2);
                textResult.setText("계산 결과 : " + result.toString());
                return false;
            }
        });

        btnDiv.setOnTouchListener(new View.OnTouchListener() {
            public boolean onTouch(View arg0, MotionEvent arg1) {
                num1 = edit1.getText().toString();
                num2 = edit2.getText().toString();
                result = Integer.parseInt(num1) / Integer.parseInt(num2);
                textResult.setText("계산 결과 : " + result.toString());
                return false;
            }
        });

        // 숫자 버튼 10개를 대입
        for (i = 0; i < numBtnIDs.length; i++) {
            numButtons[i] = (Button) findViewById(numBtnIDs[i]);
        }
        // 숫자 버튼 10개에 대해서 클릭이벤트 처리
        for (i = 0; i < numBtnIDs.length; i++) {

            final int index; // 주의! 꼭 필요함..
            index = i;

            numButtons[index].setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    // 포커스가 되어 있는 에디트텍스트에 숫자 추가
                    if (edit1.isFocused() == true) {
                        num1 = edit1.getText().toString()
                                + numButtons[index].getText().toString();
                        edit1.setText(num1);
                    } else if (edit2.isFocused() == true) {
                        num2 = edit2.getText().toString()
                                + numButtons[index].getText().toString();
                        edit2.setText(num2);
                    } else {
                        Toast.makeText(getApplicationContext(),
                                "먼저 에디트텍스트를 선택하세요",Toast.LENGTH_SHORT).show();

                    }

                }
            });

        }

    }

}