android studio计算器代码

以下是一个简单的Android Studio计算器代码：

MainActivity.java

package com.example.calculator;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {

    EditText num1, num2;
    Button add, subtract, multiply, divide;
    TextView result;

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

        num1 = findViewById(R.id.num1);
        num2 = findViewById(R.id.num2);
        add = findViewById(R.id.add);
        subtract = findViewById(R.id.subtract);
        multiply = findViewById(R.id.multiply);
        divide = findViewById(R.id.divide);
        result = findViewById(R.id.result);

        add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                double n1 = Double.parseDouble(num1.getText().toString());
                double n2 = Double.parseDouble(num2.getText().toString());
                double res = n1 + n2;
                result.setText(String.valueOf(res));
            }
        });

        subtract.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                double n1 = Double.parseDouble(num1.getText().toString());
                double n2 = Double.parseDouble(num2.getText().toString());
                double res = n1 - n2;
                result.setText(String.valueOf(res));
            }
        });

        multiply.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                double n1 = Double.parseDouble(num1.getText().toString());
                double n2 = Double.parseDouble(num2.getText().toString());
                double res = n1 * n2;
                result.setText(String.valueOf(res));
            }
        });

        divide.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                double n1 = Double.parseDouble(num1.getText().toString());
                double n2 = Double.parseDouble(num2.getText().toString());
                double res = n1 / n2;
                result.setText(String.valueOf(res));
            }
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/num1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="40dp"
        android:ems="10"
        android:hint="Enter First Number"
        android:inputType="numberDecimal"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true" />

    <EditText
        android:id="@+id/num2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/num1"
        android:layout_marginTop="20dp"
        android:ems="10"
        android:hint="Enter Second Number"
        android:inputType="numberDecimal"
        android:layout_centerHorizontal="true"/>

    <Button
        android:id="@+id/add"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/num2"
        android:layout_marginTop="20dp"
        android:text="Add"
        android:layout_centerHorizontal="true"/>

    <Button
        android:id="@+id/subtract"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/add"
        android:layout_marginTop="20dp"
        android:text="Subtract"
        android:layout_centerHorizontal="true"/>

    <Button
        android:id="@+id/multiply"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/subtract"
        android:layout_marginTop="20dp"
        android:text="Multiply"
        android:layout_centerHorizontal="true"/>

    <Button
        android:id="@+id/divide"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/multiply"
        android:layout_marginTop="20dp"
        android:text="Divide"
        android:layout_centerHorizontal="true"/>

    <TextView
        android:id="@+id/result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/divide"
        android:layout_marginTop="20dp"
        android:text="Result"
        android:textSize="24sp"
        android:layout_centerHorizontal="true"/>

</RelativeLayout>

这个计算器只支持加减乘除四个基本运算。您可以根据需要扩展它。