android studio计算器代码

以下是一个简单的 Android Studio 计算器代码，可以进行加、减、乘、除以及清零操作：

public class MainActivity extends AppCompatActivity {

    TextView resultTextView;
    Button clearButton;
    Button divideButton;
    Button multiplyButton;
    Button minusButton;
    Button plusButton;
    Button equalsButton;
    Button dotButton;
    Button zeroButton;
    Button oneButton;
    Button twoButton;
    Button threeButton;
    Button fourButton;
    Button fiveButton;
    Button sixButton;
    Button sevenButton;
    Button eightButton;
    Button nineButton;

    String operation = "";
    String firstNumber = "";
    String secondNumber = "";

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

        resultTextView = findViewById(R.id.resultTextView);
        clearButton = findViewById(R.id.clearButton);
        divideButton = findViewById(R.id.divideButton);
        multiplyButton = findViewById(R.id.multiplyButton);
        minusButton = findViewById(R.id.minusButton);
        plusButton = findViewById(R.id.plusButton);
        equalsButton = findViewById(R.id.equalsButton);
        dotButton = findViewById(R.id.dotButton);
        zeroButton = findViewById(R.id.zeroButton);
        oneButton = findViewById(R.id.oneButton);
        twoButton = findViewById(R.id.twoButton);
        threeButton = findViewById(R.id.threeButton);
        fourButton = findViewById(R.id.fourButton);
        fiveButton = findViewById(R.id.fiveButton);
        sixButton = findViewById(R.id.sixButton);
        sevenButton = findViewById(R.id.sevenButton);
        eightButton = findViewById(R.id.eightButton);
        nineButton = findViewById(R.id.nineButton);

        clearButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.setText("");
                firstNumber = "";
                secondNumber = "";
                operation = "";
            }
        });

        divideButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                operation = "/";
                if (!resultTextView.getText().toString().equals("")) {
                    firstNumber = resultTextView.getText().toString();
                    resultTextView.setText("");
                }
            }
        });

        multiplyButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                operation = "*";
                if (!resultTextView.getText().toString().equals("")) {
                    firstNumber = resultTextView.getText().toString();
                    resultTextView.setText("");
                }
            }
        });

        minusButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                operation = "-";
                if (!resultTextView.getText().toString().equals("")) {
                    firstNumber = resultTextView.getText().toString();
                    resultTextView.setText("");
                }
            }
        });

        plusButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                operation = "+";
                if (!resultTextView.getText().toString().equals("")) {
                    firstNumber = resultTextView.getText().toString();
                    resultTextView.setText("");
                }
            }
        });

        equalsButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (!firstNumber.equals("") && !resultTextView.getText().toString().equals("")) {
                    secondNumber = resultTextView.getText().toString();
                    double num1 = Double.parseDouble(firstNumber);
                    double num2 = Double.parseDouble(secondNumber);
                    double result = 0.0;
                    if (operation.equals("+")) {
                        result = num1 + num2;
                    } else if (operation.equals("-")) {
                        result = num1 - num2;
                    } else if (operation.equals("*")) {
                        result = num1 * num2;
                    } else if (operation.equals("/")) {
                        result = num1 / num2;
                    }
                    resultTextView.setText(String.valueOf(result));
                }
            }
        });

        dotButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (!resultTextView.getText().toString().contains(".")) {
                    resultTextView.append(".");
                }
            }
        });

        zeroButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("0");
            }
        });

        oneButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("1");
            }
        });

        twoButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("2");
            }
        });

        threeButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("3");
            }
        });

        fourButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("4");
            }
        });

        fiveButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("5");
            }
        });

        sixButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("6");
            }
        });

        sevenButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("7");
            }
        });

        eightButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("8");
            }
        });

        nineButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resultTextView.append("9");
            }
        });
    }
}

该代码需要一个布局文件来设置计算器的 UI 界面。在 res/layout 目录下创建一个名为 activity_main.xml 的布局文件，然后添加以下代码：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/resultTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:layout_marginBottom="16dp"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:gravity="center"
        android:textSize="36sp"/>

    <Button
        android:id="@+id/clearButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="C"
        android:textSize="36sp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_below="@+id/resultTextView"/>

    <Button
        android:id="@+id/divideButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="/"
        android:textSize="36sp"
        android:layout_toRightOf="@+id/clearButton"
        android:layout_toEndOf="@+id/clearButton"
        android:layout_below="@+id/resultTextView"/>

    <Button
        android:id="@+id/multiplyButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="*"
        android:textSize="36sp"
        android:layout_toRightOf="@+id/divideButton"
        android:layout_toEndOf="@+id/divideButton"
        android:layout_below="@+id/resultTextView"/>

    <Button
        android:id="@+id/minusButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="-"
        android:textSize="36sp"
        android:layout_toRightOf="@+id/multiplyButton"
        android:layout_toEndOf="@+id/multiplyButton"
        android:layout_below="@+id/resultTextView"/>

    <Button
        android:id="@+id/plusButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="+"
        android:textSize="36sp"
        android:layout_toRightOf="@+id/minusButton"
        android:layout_toEndOf="@+id/minusButton"
        android:layout_below="@+id/resultTextView"/>

    <Button
        android:id="@+id/equalsButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="="
        android:textSize="36sp"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:layout_below="@+id/resultTextView"/>

    <Button
        android:id="@+id/dotButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="."
        android:textSize="36sp"
        android:layout_toLeftOf="@+id/zeroButton"
        android:layout_above="@+id/equalsButton"/>

    <Button
        android:id="@+id/zeroButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="0"
        android:textSize="36sp"
        android:layout_above="@+id/equalsButton"
        android:layout_centerHorizontal="true"/>

    <Button
        android:id="@+id/oneButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="1"
        android:textSize="36sp"
        android:layout_above="@+id/fourButton"
        android:layout_alignLeft="@+id/zeroButton"
        android:layout_alignStart="@+id/zeroButton"/>

    <Button
        android:id="@+id/twoButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="2"
        android:textSize="36sp"
        android:layout_above="@+id/fiveButton"
        android:layout_toRightOf="@+id/oneButton"
        android:layout_toEndOf="@+id/oneButton"/>

    <Button
        android:id="@+id/threeButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="3"
        android:textSize="36sp"
        android:layout_above="@+id/sixButton"
        android:layout_toRightOf="@+id/twoButton"
        android:layout_toEndOf="@+id/twoButton"/>

    <Button
        android:id="@+id/fourButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="4"
        android:textSize="36sp"
        android:layout_above="@+id/sevenButton"
        android:layout_alignLeft="@+id/oneButton"
        android:layout_alignStart="@+id/oneButton"/>

    <Button
        android:id="@+id/fiveButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="5"
        android:textSize="36sp"
        android:layout_above="@+id/eightButton"
        android:layout_toRightOf="@+id/fourButton"
        android:layout_toEndOf="@+id/fourButton"/>

    <Button
        android:id="@+id/sixButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="6"
        android:textSize="36sp"
        android:layout_above="@+id/nineButton"
        android:layout_toRightOf="@+id/fiveButton"
        android:layout_toEndOf="@+id/fiveButton"/>

    <Button
        android:id="@+id/sevenButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="7"
        android:textSize="36sp"
        android:layout_alignLeft="@+id/fourButton"
        android:layout_alignStart="@+id/fourButton"
        android:layout_above="@+id/clearButton"/>

    <Button
        android:id="@+id/eightButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="8"
        android:textSize="36sp"
        android:layout_alignLeft="@+id/fiveButton"
        android:layout_alignStart="@+id/fiveButton"
        android:layout_above="@+id/clearButton"
        android:layout_toRightOf="@+id/sevenButton"
        android:layout_toEndOf="@+id/sevenButton"/>

    <Button
        android:id="@+id/nineButton"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:text="9"
        android:textSize="36sp"
        android:layout_alignLeft="@+id/sixButton"
        android:layout_alignStart="@+id/sixButton"
        android:layout_above="@+id/clearButton"
        android:layout_toRightOf="@+id/eightButton"
        android:layout_toEndOf="@+id/eightButton"/>

</RelativeLayout>