帮我写一个安卓计算器可以实现连乘连加的MainActivity代码

好的，以下是一个简单的安卓计算器实现连乘连加的 MainActivity 代码：

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private EditText etResult;
    private Button btnClear, btnDelete, btnDivide, btnMultiply, btnMinus, btnPlus, btnEqual;
    private Button[] btnNums;

    private StringBuilder sb = new StringBuilder();

    private double num1 = 0, num2 = 0;
    private int operator = 0;

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

        etResult = findViewById(R.id.et_result);
        btnClear = findViewById(R.id.btn_clear);
        btnDelete = findViewById(R.id.btn_delete);
        btnDivide = findViewById(R.id.btn_divide);
        btnMultiply = findViewById(R.id.btn_multiply);
        btnMinus = findViewById(R.id.btn_minus);
        btnPlus = findViewById(R.id.btn_plus);
        btnEqual = findViewById(R.id.btn_equal);

        btnNums = new Button[10];
        for (int i = 0; i < 10; i++) {
            String btnId = "btn_" + i;
            int resId = getResources().getIdentifier(btnId, "id", getPackageName());
            btnNums[i] = findViewById(resId);
        }

        btnClear.setOnClickListener(this);
        btnDelete.setOnClickListener(this);
        btnDivide.setOnClickListener(this);
        btnMultiply.setOnClickListener(this);
        btnMinus.setOnClickListener(this);
        btnPlus.setOnClickListener(this);
        btnEqual.setOnClickListener(this);

        for (Button btnNum : btnNums) {
            btnNum.setOnClickListener(this);
        }
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_clear:
                clear();
                break;
            case R.id.btn_delete:
                delete();
                break;
            case R.id.btn_divide:
                operator = 4;
                num1 = Double.parseDouble(sb.toString());
                sb.delete(0, sb.length());
                break;
            case R.id.btn_multiply:
                operator = 3;
                num1 = Double.parseDouble(sb.toString());
                sb.delete(0, sb.length());
                break;
            case R.id.btn_minus:
                operator = 2;
                num1 = Double.parseDouble(sb.toString());
                sb.delete(0, sb.length());
                break;
            case R.id.btn_plus:
                operator = 1;
                num1 = Double.parseDouble(sb.toString());
                sb.delete(0, sb.length());
                break;
            case R.id.btn_equal:
                num2 = Double.parseDouble(sb.toString());
                sb.delete(0, sb.length());
                double result = 0;
                switch (operator) {
                    case 1:
                        result = num1 + num2;
                        break;
                    case 2:
                        result = num1 - num2;
                        break;
                    case 3:
                        result = num1 * num2;
                        break;
                    case 4:
                        result = num1 / num2;
                        break;
                }
                etResult.setText(String.valueOf(result));
                break;
            default:
                sb.append(((Button) v).getText());
                etResult.setText(sb.toString());
                break;
        }
    }

    private void clear() {
        num1 = 0;
        num2 = 0;
        operator = 0;
        sb.delete(0, sb.length());
        etResult.setText("");
    }

    private void delete() {
        if (sb.length() > 0) {
            sb.deleteCharAt(sb.length() - 1);
            etResult.setText(sb.toString());
        }
    }
}

这个计算器可以实现加、减、乘、除和连乘连加的功能。在按钮点击事件中，我们可以根据操作符进行相应的运算。当用户点击等号时，我们可以根据操作符计算出结果并显示在 EditText 中。