用android studio实现一个计算器

好的，您可以使用 Android Studio 中的 Java 语言编写一个简单的计算器应用程序。以下是一个示例代码：

public class CalculatorActivity extends AppCompatActivity {

    private EditText mEditText;
    private Button mButton0, mButton1, mButton2, mButton3, mButton4, mButton5, mButton6, mButton7, mButton8, mButton9;
    private Button mButtonAdd, mButtonSubtract, mButtonMultiply, mButtonDivide, mButtonEquals, mButtonClear;

    private double mValueOne = Double.NaN;
    private double mValueTwo;

    private static final char ADDITION = '+';
    private static final char SUBTRACTION = '-';
    private static final char MULTIPLICATION = '*';
    private static final char DIVISION = '/';

    private char mAction;

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

        mEditText = findViewById(R.id.editText);

        mButton0 = findViewById(R.id.button0);
        mButton1 = findViewById(R.id.button1);
        mButton2 = findViewById(R.id.button2);
        mButton3 = findViewById(R.id.button3);
        mButton4 = findViewById(R.id.button4);
        mButton5 = findViewById(R.id.button5);
        mButton6 = findViewById(R.id.button6);
        mButton7 = findViewById(R.id.button7);
        mButton8 = findViewById(R.id.button8);
        mButton9 = findViewById(R.id.button9);

        mButtonAdd = findViewById(R.id.buttonAdd);
        mButtonSubtract = findViewById(R.id.buttonSubtract);
        mButtonMultiply = findViewById(R.id.buttonMultiply);
        mButtonDivide = findViewById(R.id.buttonDivide);
        mButtonEquals = findViewById(R.id.buttonEquals);
        mButtonClear = findViewById(R.id.buttonClear);

        mButton0.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "0");
            }
        });

        mButton1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "1");
            }
        });

        mButton2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "2");
            }
        });

        mButton3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "3");
            }
        });

        mButton4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "4");
            }
        });

        mButton5.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "5");
            }
        });

        mButton6.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "6");
            }
        });

        mButton7.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "7");
            }
        });

        mButton8.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "8");
            }
        });

        mButton9.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText(mEditText.getText() + "9");
            }
        });

        mButtonAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                computeCalculation();
                mAction = ADDITION;
                mEditText.setText(null);
            }
        });

        mButtonSubtract.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                computeCalculation();
                mAction = SUBTRACTION;
                mEditText.setText(null);
            }
        });

        mButtonMultiply.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                computeCalculation();
                mAction = MULTIPLICATION;
                mEditText.setText(null);
            }
        });

        mButtonDivide.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                computeCalculation();
                mAction = DIVISION;
                mEditText.setText(null);
            }
        });

        mButtonEquals.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                computeCalculation();
                mEditText.setText(String.valueOf(mValueOne));
                mValueOne = Double.NaN;
                mAction = '0';
            }
        });

        mButtonClear.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mEditText.setText("");
                mValueOne = Double.NaN;
                mValueTwo = Double.NaN;
            }
        });
    }

    private void computeCalculation() {
        if (!Double.isNaN(mValueOne)) {
            mValueTwo = Double.parseDouble(mEditText.getText().toString());

            switch (mAction) {
                case ADDITION:
                    mValueOne = mValueOne + mValueTwo;
                    break;
                case SUBTRACTION:
                    mValueOne = mValueOne - mValueTwo;
                    break;
                case MULTIPLICATION:
                    mValueOne = mValueOne * mValueTwo;
                    break;
                case DIVISION:
                    mValueOne = mValueOne / mValueTwo;
                    break;
                default:
                    break;
            }
        } else {
            mValueOne = Double.parseDouble(mEditText.getText().toString());
        }
    }
}

这段代码实现了一个简单的计算器应用程序，包括数字按钮、加减乘除按钮、等于按钮和清除按钮。当用户按下数字按钮时，数字将显示在 EditText 中。当用户按下加减乘除按钮时，计算器将执行相应的操作。当用户按下等于按钮时，计算器将计算结果并显示在 EditText 中。当用户按下清除按钮时，EditText 将被清空。