Androidstudio生成一个计算器代码

以下是一个简单的 Android Studio 计算器应用程序的代码示例：

1. 创建一个新的 Android Studio 项目并设置基本信息（包名称、应用名称等）。

2. 打开 activity_main.xml 文件，并将以下代码添加到其中：

<?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_margin="16dp"
        android:background="@color/colorPrimaryDark"
        android:gravity="right"
        android:textColor="@android:color/white"
        android:textSize="32sp"
        android:textStyle="bold" />

    <GridLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/resultTextView"
        android:columnCount="4"
        android:rowCount="5"
        android:orientation="horizontal">

        <Button
            android:id="@+id/buttonClear"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="C"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonBackspace"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="&lt;-"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonPercent"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="%"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonDivide"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="/"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonSeven"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="7"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonEight"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="8"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonNine"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="9"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonMultiply"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="*"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonFour"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="4"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonFive"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="5"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonSix"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="6"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonMinus"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="-"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonOne"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="1"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonTwo"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="2"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonThree"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="3"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonPlus"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="+"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonNegative"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="+/-"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonZero"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="0"
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonDot"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="1"
            android:text="."
            android:textSize="24sp" />

        <Button
            android:id="@+id/buttonEquals"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_columnWeight="1"
            android:layout_rowWeight="2"
            android:text="="
            android:textSize="24sp" />

    </GridLayout>

</RelativeLayout>

3. 打开 MainActivity.java 文件，并将以下代码添加到其中：

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private TextView resultTextView;
    private Button buttonClear, buttonBackspace, buttonPercent, buttonDivide, buttonSeven,
            buttonEight, buttonNine, buttonMultiply, buttonFour, buttonFive, buttonSix,
            buttonMinus, buttonOne, buttonTwo, buttonThree, buttonPlus, buttonNegative,
            buttonZero, buttonDot, buttonEquals;

    private String currentNumber = "";
    private String operator = "";
    private double result = 0;

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

        resultTextView = findViewById(R.id.resultTextView);
        buttonClear = findViewById(R.id.buttonClear);
        buttonBackspace = findViewById(R.id.buttonBackspace);
        buttonPercent = findViewById(R.id.buttonPercent);
        buttonDivide = findViewById(R.id.buttonDivide);
        buttonSeven = findViewById(R.id.buttonSeven);
        buttonEight = findViewById(R.id.buttonEight);
        buttonNine = findViewById(R.id.buttonNine);
        buttonMultiply = findViewById(R.id.buttonMultiply);
        buttonFour = findViewById(R.id.buttonFour);
        buttonFive = findViewById(R.id.buttonFive);
        buttonSix = findViewById(R.id.buttonSix);
        buttonMinus = findViewById(R.id.buttonMinus);
        buttonOne = findViewById(R.id.buttonOne);
        buttonTwo = findViewById(R.id.buttonTwo);
        buttonThree = findViewById(R.id.buttonThree);
        buttonPlus = findViewById(R.id.buttonPlus);
        buttonNegative = findViewById(R.id.buttonNegative);
        buttonZero = findViewById(R.id.buttonZero);
        buttonDot = findViewById(R.id.buttonDot);
        buttonEquals = findViewById(R.id.buttonEquals);

        buttonClear.setOnClickListener(this);
        buttonBackspace.setOnClickListener(this);
        buttonPercent.setOnClickListener(this);
        buttonDivide.setOnClickListener(this);
        buttonSeven.setOnClickListener(this);
        buttonEight.setOnClickListener(this);
        buttonNine.setOnClickListener(this);
        buttonMultiply.setOnClickListener(this);
        buttonFour.setOnClickListener(this);
        buttonFive.setOnClickListener(this);
        buttonSix.setOnClickListener(this);
        buttonMinus.setOnClickListener(this);
        buttonOne.setOnClickListener(this);
        buttonTwo.setOnClickListener(this);
        buttonThree.setOnClickListener(this);
        buttonPlus.setOnClickListener(this);
        buttonNegative.setOnClickListener(this);
        buttonZero.setOnClickListener(this);
        buttonDot.setOnClickListener(this);
        buttonEquals.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.buttonClear:
                currentNumber = "";
                operator = "";
                result = 0;
                resultTextView.setText("");
                break;

            case R.id.buttonBackspace:
                if (currentNumber.length() > 0) {
                    currentNumber = currentNumber.substring(0, currentNumber.length() - 1);
                    resultTextView.setText(currentNumber);
                }
                break;

            case R.id.buttonPercent:
                if (currentNumber.length() > 0) {
                    double percentValue = Double.parseDouble(currentNumber) / 100;
                    currentNumber = String.valueOf(percentValue);
                    resultTextView.setText(currentNumber);
                }
                break;

            case R.id.buttonDivide:
            case R.id.buttonMultiply:
            case R.id.buttonMinus:
            case R.id.buttonPlus:
                if (operator.isEmpty()) {
                    operator = ((Button) v).getText().toString();
                    result = Double.parseDouble(currentNumber);
                    currentNumber = "";
                } else {
                    calculate();
                    operator = ((Button) v).getText().toString();
                }
                break;

            case R.id.buttonEquals:
                calculate();
                break;

            default:
                currentNumber += ((Button) v).getText().toString();
                resultTextView.setText(currentNumber);
                break;
        }
    }

    private void calculate() {
        if (currentNumber.length() > 0) {
            double number = Double.parseDouble(currentNumber);

            switch (operator) {
                case "/":
                    result /= number;
                    break;

                case "*":
                    result *= number;
                    break;

                case "-":
                    result -= number;
                    break;

                case "+":
                    result += number;
                    break;
            }

            currentNumber = String.valueOf(result);
            resultTextView.setText(currentNumber);
            operator = "";
        }
    }
}

4. 运行应用程序并测试它。现在你有了一个简单的 Android Studio 计算器应用程序！