安卓（Android studio）编写一个计算器，可以连续加减乘除，可加小数点，不包含括号以及加减乘除优先算法

好的，以下是一个简单的安卓计算器代码示例：

1. 在 XML 文件中创建布局：

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/resultTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:textAlignment="center"/>

    <LinearLayout
        android:layout_below="@id/resultTextView"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:weightSum="4">

        <Button
            android:id="@+id/button1"
            android:text="1"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/button2"
            android:text="2"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/button3"
            android:text="3"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/buttonAdd"
            android:text="+"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />
    </LinearLayout>

    <LinearLayout
        android:layout_below="@id/button1"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:weightSum="4">

        <Button
            android:id="@+id/button4"
            android:text="4"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/button5"
            android:text="5"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/button6"
            android:text="6"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/buttonSubtract"
            android:text="-"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />
    </LinearLayout>

    <LinearLayout
        android:layout_below="@id/button4"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:weightSum="4">

        <Button
            android:id="@+id/button7"
            android:text="7"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/button8"
            android:text="8"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/button9"
            android:text="9"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/buttonMultiply"
            android:text="*"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />
    </LinearLayout>

    <LinearLayout
        android:layout_below="@id/button7"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:weightSum="4">

        <Button
            android:id="@+id/buttonClear"
            android:text="C"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/button0"
            android:text="0"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/buttonDecimal"
            android:text="."
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content" />

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

    </LinearLayout>

    <Button
        android:id="@+id/buttonEqual"
        android:text="="
        android:layout_below="@id/buttonClear"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</RelativeLayout>

2. 在 Java 文件中添加以下代码：

public class MainActivity extends AppCompatActivity {

    private TextView resultTextView;
    private String operand1 = "";
    private String operand2 = "";
    private String operator = "";
    private String result = "";

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

        resultTextView = findViewById(R.id.resultTextView);

        // Set up number buttons
        findViewById(R.id.button0).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("0");
            }
        });

        findViewById(R.id.button1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("1");
            }
        });

        findViewById(R.id.button2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("2");
            }
        });

        findViewById(R.id.button3).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("3");
            }
        });

        findViewById(R.id.button4).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("4");
            }
        });

        findViewById(R.id.button5).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("5");
            }
        });

        findViewById(R.id.button6).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("6");
            }
        });

        findViewById(R.id.button7).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("7");
            }
        });

        findViewById(R.id.button8).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("8");
            }
        });

        findViewById(R.id.button9).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed("9");
            }
        });

        findViewById(R.id.buttonDecimal).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                numberPressed(".");
            }
        });

        // Set up operator buttons
        findViewById(R.id.buttonAdd).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                operatorPressed("+");
            }
        });

        findViewById(R.id.buttonSubtract).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                operatorPressed("-");
            }
        });

        findViewById(R.id.buttonMultiply).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                operatorPressed("*");
            }
        });

        findViewById(R.id.buttonDivide).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                operatorPressed("/");
            }
        });

        // Set up clear button
        findViewById(R.id.buttonClear).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                clearPressed();
            }
        });

        // Set up equal button
        findViewById(R.id.buttonEqual).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                equalPressed();
            }
        });
    }

    private void numberPressed(String number) {
        if (operator.isEmpty()) {
            operand1 += number;
            resultTextView.setText(operand1);
        } else {
            operand2 += number;
            resultTextView.setText(operand2);
        }
    }

    private void operatorPressed(String operator) {
        this.operator = operator;
        resultTextView.setText(operator);
    }

    private void clearPressed() {
        operand1 = "";
        operand2 = "";
        operator = "";
        result = "";
        resultTextView.setText("0");
    }

    private void equalPressed() {
        if (!operand1.isEmpty() && !operand2.isEmpty() && !operator.isEmpty()) {
            double num1 = Double.parseDouble(operand1);
            double num2 = Double.parseDouble(operand2);

            switch (operator) {
                case "+":
                    result = String.valueOf(num1 + num2);
                    break;
                case "-":
                    result = String.valueOf(num1 - num2);
                    break;
                case "*":
                    result = String.valueOf(num1 * num2);
                    break;
                case "/":
                    if (num2 == 0) {
                        result = "Error";
                    } else {
                        result = String.valueOf(num1 / num2);
                    }
                    break;
            }

            resultTextView.setText(result);

            operand1 = result;
            operand2 = "";
            operator = "";
            result = "";
        }
    }
}

这样就可以实现一个简单的安卓计算器了。