https://github.com/xjhqre/android_calculator
制作步骤 1. 创建按钮图片 1.1. 退格图形1.2. 等号图形
2. 布局文件
3. java代码
package com.example.work2;
import android.annotation.SuppressLint;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.TextView;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
Button btn_1; // 数字1
Button btn_2; // 数字2
Button btn_3; // 数字3
Button btn_4; // 数字4
Button btn_5; // 数字5
Button btn_6; // 数字6
Button btn_7; // 数字7
Button btn_8; // 数字8
Button btn_9; // 数字9
Button btn_0; // 数字0
Button add; // +号
Button sub; // -号
Button mul; // *号
Button div; // 除号
Button dot; // 小数点
ImageButton equ; // =号
ImageButton backspace; // 退格符号
Button percentSign; // %
Button ac; //清除
TextView result; // 显示结果
TextView record; // 显示记录
String record_string; // String类型的运算步骤
ArrayList operatorStack = new ArrayList<>();
ArrayList operandStack = new ArrayList<>();
ArrayList operatorList = new ArrayList<>();
int previousOperatorSubscript = 0;
int nextOperatorSubscript = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
operatorList.add("+");
operatorList.add("-");
operatorList.add("×");
operatorList.add("÷");
// 获取页面上的控件
btn_1 = findViewById(R.id.btn_1);
btn_2 = findViewById(R.id.btn_2);
btn_3 = findViewById(R.id.btn_3);
btn_4 = findViewById(R.id.btn_4);
btn_5 = findViewById(R.id.btn_5);
btn_6 = findViewById(R.id.btn_6);
btn_7 = findViewById(R.id.btn_7);
btn_8 = findViewById(R.id.btn_8);
btn_9 = findViewById(R.id.btn_9);
btn_0 = findViewById(R.id.btn_0);
add = findViewById(R.id.btn_add);
sub = findViewById(R.id.btn_sub);
mul = findViewById(R.id.btn_mul);
div = findViewById(R.id.btn_div);
equ = findViewById(R.id.btn_equ);
dot = findViewById(R.id.btn_dot);
ac = findViewById(R.id.btn_clear);
percentSign = findViewById(R.id.btn_percentSign);
backspace = findViewById(R.id.btn_delete);
record = findViewById(R.id.et_record);
result = findViewById(R.id.et_result);
// 按钮的单击事件
btn_1.setOnClickListener(new Click());
btn_2.setOnClickListener(new Click());
btn_3.setOnClickListener(new Click());
btn_4.setOnClickListener(new Click());
btn_5.setOnClickListener(new Click());
btn_6.setOnClickListener(new Click());
btn_7.setOnClickListener(new Click());
btn_8.setOnClickListener(new Click());
btn_9.setOnClickListener(new Click());
btn_0.setOnClickListener(new Click());
add.setOnClickListener(new Click());
sub.setOnClickListener(new Click());
mul.setOnClickListener(new Click());
div.setOnClickListener(new Click());
equ.setOnClickListener(new Click());
dot.setOnClickListener(new Click());
ac.setOnClickListener(new Click());
backspace.setOnClickListener(new Click());
percentSign.setOnClickListener(new Click());
}
// 设置按钮点击后的监听
class Click implements View.OnClickListener {
@RequiresApi(api = Build.VERSION_CODES.N)
@SuppressLint("NonConstantResourceId")
public void onClick(View v) {
switch (v.getId()) { //switch循环获取点击按钮后的值
case R.id.btn_0: //获取，0-9、小数点，并在编辑框显示
record_string = record.getText().toString();
record_string += "0";
record.setText(record_string);
break;
case R.id.btn_1:
record_string = record.getText().toString();
record_string += "1";
record.setText(record_string);
break;
case R.id.btn_2:
record_string = record.getText().toString();
record_string += "2";
record.setText(record_string);
break;
case R.id.btn_3:
record_string = record.getText().toString();
record_string += "3";
record.setText(record_string);
break;
case R.id.btn_4:
record_string = record.getText().toString();
record_string += "4";
record.setText(record_string);
break;
case R.id.btn_5:
record_string = record.getText().toString();
record_string += "5";
record.setText(record_string);
break;
case R.id.btn_6:
record_string = record.getText().toString();
record_string += "6";
record.setText(record_string);
break;
case R.id.btn_7:
record_string = record.getText().toString();
record_string += "7";
record.setText(record_string);
break;
case R.id.btn_8:
record_string = record.getText().toString();
record_string += "8";
record.setText(record_string);
break;
case R.id.btn_9:
record_string = record.getText().toString();
record_string += "9";
record.setText(record_string);
break;
case R.id.btn_dot:
record_string = record.getText().toString();
record_string += ".";
record.setText(record_string);
break;
case R.id.btn_add: //判断，使用加减乘除的操作符
record_string = record.getText().toString();
record_string += "+";
record.setText(record_string);
break;
case R.id.btn_sub:
record_string = record.getText().toString();
record_string += "-";
record.setText(record_string);
break;
case R.id.btn_mul:
record_string = record.getText().toString();
record_string += "×";
record.setText(record_string);
break;
case R.id.btn_div:
record_string = record.getText().toString();
record_string += "÷";
record.setText(record_string);
break;
case R.id.btn_delete:
record_string = record.getText().toString();
if (record_string.length() > 0) {
record_string = record_string.substring(0, record_string.length() - 1);
record.setText(record_string);
}
break;
case R.id.btn_clear: //清除，将编辑框文本显示为空
record.setText(null);
result.setText(null);
previousOperatorSubscript = 0;
nextOperatorSubscript = 0;
operandStack.clear();
operatorStack.clear();
break;
case R.id.btn_equ: //计算，以操作符为判断，选择所需的运算，并将结果输出
if ("错误".equals(result.getText().toString())) return;
record_string = record.getText().toString();
if ("".equals(record_string)) return;
// 遍历运算记录，调整运算优先级，使运算记录中只剩下加减操作
for (int i = 0; i < record_string.length(); i++) {
String operator = String.valueOf(record_string.charAt(i));
// 如果遍历到运算符
if (operatorList.contains(operator)) {
// 插入新的操作数
nextOperatorSubscript = i;
try {
operandStack.add(Double.parseDouble(record_string.substring(previousOperatorSubscript, nextOperatorSubscript)));
} catch (Exception e) {
result.setText("错误");
return;
}
previousOperatorSubscript = nextOperatorSubscript + 1;
// 如果运算符栈中没有运算符
if (operatorStack.size() == 0) {
operatorStack.add(operator);
} else {
// 找出上一个运算符
String pre_operator = operatorStack.get(operatorStack.size() - 1);
if ("×".equals(pre_operator)) {
// 移除上一个运算符
operatorStack.remove(operatorStack.size() - 1);
Double num1 = operandStack.get(operandStack.size() - 2);
Double num2 = operandStack.get(operandStack.size() - 1);
operandStack.remove(operandStack.size() - 1);
operandStack.remove(operandStack.size() - 1);
operandStack.add(num1 * num2);
} else if ("÷".equals(pre_operator)) {
// 移除上一个运算符
operatorStack.remove(operatorStack.size() - 1);
Double num1 = operandStack.get(operandStack.size() - 2);
Double num2 = operandStack.get(operandStack.size() - 1);
operandStack.remove(operandStack.size() - 1);
operandStack.remove(operandStack.size() - 1);
operandStack.add(num1 / num2);
}
// 插入新的运算符
operatorStack.add(operator);
}
} else if (i == record.length() - 1) {
// 如果遍历到末尾，添加最后一个操作数
try {
operandStack.add(Double.parseDouble(record_string.substring(previousOperatorSubscript, record.length())));
} catch (Exception e) {
result.setText("错误");
return;
}
// 如果上一个操作数是乘法或除法，则进行运算
if (operatorStack.size() > 0) {
String pre_operator = operatorStack.get(operatorStack.size() - 1);
if ("×".equals(pre_operator)) {
// 移除上一个运算符
operatorStack.remove(operatorStack.size() - 1);
Double num1 = operandStack.get(operandStack.size() - 2);
Double num2 = operandStack.get(operandStack.size() - 1);
operandStack.remove(operandStack.size() - 1);
operandStack.remove(operandStack.size() - 1);
operandStack.add(num1 * num2);
} else if ("÷".equals(pre_operator)) {
// 移除上一个运算符
operatorStack.remove(operatorStack.size() - 1);
Double num1 = operandStack.get(operandStack.size() - 2);
Double num2 = operandStack.get(operandStack.size() - 1);
operandStack.remove(operandStack.size() - 1);
operandStack.remove(operandStack.size() - 1);
operandStack.add(num1 / num2);
}
}
}
}
// 判断两个栈是否合法
if (operandStack.size() != operatorStack.size() + 1) {
result.setText("错误");
return;
}
// 完成剩余栈中的运算
for (int i = 0; i < operatorStack.size(); i++) {
String operator = operatorStack.get(i);
if ("+".equals(operator)) {
Double num1 = operandStack.get(0);
Double num2 = operandStack.get(1);
operandStack.remove(0);
operandStack.remove(0);
operandStack.add(num1 + num2);
} else if ("-".equals(operator)) {
Double num1 = operandStack.get(0);
Double num2 = operandStack.get(1);
operandStack.remove(0);
operandStack.remove(0);
operandStack.add(0, num1 - num2);
} else if ("×".equals(operator)) {
Double num1 = operandStack.get(0);
Double num2 = operandStack.get(1);
operandStack.remove(0);
operandStack.remove(0);
operandStack.add(0, num1 * num2);
} else if ("÷".equals(operator)) {
Double num1 = operandStack.get(0);
Double num2 = operandStack.get(1);
operandStack.remove(0);
operandStack.remove(0);
operandStack.add(0, num1 / num2);
}
}
result.setText(String.valueOf(operandStack.get(0))); //将结果完整输出
record.setText(String.valueOf(operandStack.get(0)));
previousOperatorSubscript = 0;
nextOperatorSubscript = 0;
operandStack.clear();
operatorStack.clear();
break;
default:
break;
}
}
}
}
效果演示
1. 连续加法
2. 连续减法
3. 连续乘法
4. 连续除法
5. 优先级运算
6. 退格功能
7. 错误提示
