android studio 连续加减乘除无优先级计算器代码

以下是一个简单的基于 Android Studio 的连续加减乘除无优先级计算器代码：

1. 在布局文件中添加一个 TextView 用于显示计算结果，以及四个 Button 用于输入数字和操作符。

2. 在 MainActivity 类中定义四个变量用于存储计算器的状态：

private String currentNumber = ""; // 当前输入的数字
private String lastOperator = ""; // 上一个操作符
private double result = 0; // 当前计算结果
private boolean isResultDisplayed = false; // 当前计算结果是否已经显示

3. 为四个 Button 添加 onClickListener，分别处理数字和操作符的输入。例如，输入数字时追加到 currentNumber 中，输入操作符时根据 lastOperator 计算上一个数字和当前数字的结果，并将结果存储到 result 中。

// 处理数字的输入
public void onNumberClick(View view) {
    String buttonText = ((Button) view).getText().toString();
    if (isResultDisplayed) {
        currentNumber = "";
        isResultDisplayed = false;
    }
    currentNumber += buttonText;
    updateResultDisplay(currentNumber);
}

// 处理操作符的输入
public void onOperatorClick(View view) {
    String buttonText = ((Button) view).getText().toString();
    if (lastOperator.equals("")) {
        result = Double.parseDouble(currentNumber);
    } else {
        double current = Double.parseDouble(currentNumber);
        switch (lastOperator) {
            case "+":
                result += current;
                break;
            case "-":
                result -= current;
                break;
            case "*":
                result *= current;
                break;
            case "/":
                result /= current;
                break;
        }
    }
    currentNumber = "";
    lastOperator = buttonText;
    updateResultDisplay(String.valueOf(result));
}

4. 添加一个 updateResultDisplay 方法用于更新 TextView 中的计算结果。

// 更新计算结果的显示
private void updateResultDisplay(String resultString) {
    TextView resultTextView = findViewById(R.id.result_text_view);
    resultTextView.setText(resultString);
}

完整代码如下：

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private String currentNumber = ""; // 当前输入的数字
    private String lastOperator = ""; // 上一个操作符
    private double result = 0; // 当前计算结果
    private boolean isResultDisplayed = false; // 当前计算结果是否已经显示

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

    // 处理数字的输入
    public void onNumberClick(View view) {
        String buttonText = ((Button) view).getText().toString();
        if (isResultDisplayed) {
            currentNumber = "";
            isResultDisplayed = false;
        }
        currentNumber += buttonText;
        updateResultDisplay(currentNumber);
    }

    // 处理操作符的输入
    public void onOperatorClick(View view) {
        String buttonText = ((Button) view).getText().toString();
        if (lastOperator.equals("")) {
            result = Double.parseDouble(currentNumber);
        } else {
            double current = Double.parseDouble(currentNumber);
            switch (lastOperator) {
                case "+":
                    result += current;
                    break;
                case "-":
                    result -= current;
                    break;
                case "*":
                    result *= current;
                    break;
                case "/":
                    result /= current;
                    break;
            }
        }
        currentNumber = "";
        lastOperator = buttonText;
        updateResultDisplay(String.valueOf(result));
    }

    // 处理等号的输入
    public void onEqualClick(View view) {
        if (!lastOperator.equals("")) {
            double current = Double.parseDouble(currentNumber);
            switch (lastOperator) {
                case "+":
                    result += current;
                    break;
                case "-":
                    result -= current;
                    break;
                case "*":
                    result *= current;
                    break;
                case "/":
                    result /= current;
                    break;
            }
        }
        currentNumber = "";
        lastOperator = "";
        updateResultDisplay(String.valueOf(result));
        isResultDisplayed = true;
    }

    // 处理清除的输入
    public void onClearClick(View view) {
        currentNumber = "";
        lastOperator = "";
        result = 0;
        updateResultDisplay("");
        isResultDisplayed = false;
    }

    // 更新计算结果的显示
    private void updateResultDisplay(String resultString) {
        TextView resultTextView = findViewById(R.id.result_text_view);
        resultTextView.setText(resultString);
    }
}

activity_main.xml

<LinearLayout
    ...
    android:orientation="vertical">

    <TextView
        ...
        android:id="@+id/result_text_view"
        android:textSize="32sp"
        android:textStyle="bold"
        android:gravity="right"
        android:padding="16dp"
        android:textColor="@android:color/black"
        android:text=""/>

    <LinearLayout
        ...
        android:orientation="horizontal">

        <Button
            ...
            android:text="7"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="8"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="9"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="/"
            android:onClick="onOperatorClick"/>

    </LinearLayout>

    <LinearLayout
        ...
        android:orientation="horizontal">

        <Button
            ...
            android:text="4"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="5"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="6"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="*"
            android:onClick="onOperatorClick"/>

    </LinearLayout>

    <LinearLayout
        ...
        android:orientation="horizontal">

        <Button
            ...
            android:text="1"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="2"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="3"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="-"
            android:onClick="onOperatorClick"/>

    </LinearLayout>

    <LinearLayout
        ...
        android:orientation="horizontal">

        <Button
            ...
            android:text="0"
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="."
            android:onClick="onNumberClick"/>

        <Button
            ...
            android:text="C"
            android:onClick="onClearClick"/>

        <Button
            ...
            android:text="+"
            android:onClick="onOperatorClick"/>

    </LinearLayout>

    <Button
        ...
        android:text="="
        android:onClick="onEqualClick"/>

</LinearLayout>