Android实现简单计算器源码
16lz
2021-01-23
最近写了一个计算器，实现了一些简单功能，先贴图。
源码如下：
java文件：
package com.example.admin.caculator;import java.util.*;import java.util.regex.Matcher;import java.util.regex.Pattern;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;/** * @author yiyi * 可能有些许Bug，烦请指正。 * * */public class MainActivity extends AppCompatActivity { private int[] idNum = {R.id.txt0, R.id.txt1, R.id.txt2, R.id.txt3, R.id.txt4, R.id.txt5, R.id.txt6, R.id.txt7, R.id.txt8, R.id.txt9}; //数字Number输入 private int[] idCal = {R.id.txtPlus, R.id.txtMinus, R.id.txtMul, R.id.txtDiv,R.id.txtLeft,R.id.txtRight,R.id.txtDot}; //运算符 private Button[] buttonsCal = new Button[idCal.length]; private Button[] buttonsNum = new Button[idNum.length]; private Button buttonEqu; //= private Button buttonClear; // AC private Button buttonDel; private EditText input ; private TextView output; private static String Text; @Override /** * EditText为输入字符行， * TextView为结果。 */ protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); input = (EditText)findViewById(R.id.input); input.setText(""); input.setEnabled(false); output = (TextView) findViewById(R.id.output); output.setText(""); buttonEqu = (Button)findViewById(R.id.txtIs); buttonEqu.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { output.setText(new Calculate(input.getText().toString()).str); } }); buttonClear = (Button) findViewById(R.id.txtClear); buttonClear.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { input.setText(""); output.setText(""); } }); buttonDel = (Button) findViewById(R.id.txtDel); buttonDel.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (!input.getText().toString().isEmpty() ) { Text = input.getText().toString(); Text = Text.substring(0, Text.length() - 1); input.setText(Text); } } });/** * 注册单击事件 */ for (int idcal = 0; idcal < idCal.length; idcal++) { buttonsCal[idcal] = (Button) findViewById(idCal[idcal]); buttonsCal[idcal].setOnClickListener(new CalOnClick(buttonsCal[idcal].getText().toString())); } for (int i = 0; i < idNum.length; i++) { buttonsNum[i] = (Button) findViewById(idNum[i]); buttonsNum[i].setOnClickListener(new NumberOnClick(buttonsNum[i].getText().toString())); } } //继承OnClick接口 class NumberOnClick implements View.OnClickListener { String Msg; /** * * @param msg 点击按钮传入字符 */ public NumberOnClick(String msg) { Msg = msg; } @Override public void onClick(View v) { if (!output.getText().toString().equals("")) { input.setText(""); output.setText(""); } input.append(Msg); } } class CalOnClick implements View.OnClickListener{ String Msg; String[] calSymbol = {"+", "-", "*", "/","."}; public CalOnClick(String msg) { Msg = msg; } @Override public void onClick(View v) { if (!output.getText().toString().equals("")) { input.setText(""); output.setText(""); } // 检查是否运算符重复输入 for (int i = 0; i < calSymbol.length; i++) { if (Msg.equals(calSymbol[i])) { if (input.getText().toString().split("") [input.getText().toString().split("").length - 1].equals(calSymbol[i])) { Msg = ""; } } } input.append(Msg); } } /** * 运算类，返回一个String结果 */ public class Calculate { public String s1; StringBuilder str; public Calculate(String m) { this.s1 = m; try { eval(); } catch (Exception e) { str.delete(0, str.length()); str.append("ERROR"); } } /** *中缀表达式转后缀表达式 * *遍历中缀的list *1、数字时，加入后缀list *2、“(”时，压栈 *3、 若为 ')'，则依次弹栈,把弹出的运算符加入后缀表达式中，直到出现'('； *4、若为运算符，对做如下处置 * 1、如果栈为空，则压栈 * 2、如果栈不为空: * 1、stack.peek().equals("(") 则压栈 * 2、比较str和stack.peek()的优先级 * 1、如果>,则运算符压栈 * 2、<=的情况：当栈不为空时: * 1、stack.peek()是左括号，压栈 * 2、<=,把peek加入后缀表达式，弹栈 * 3、>，把运算符压栈，停止对栈的操作 * 执行完栈的操作之后，还得判断:如果栈为空,运算符压栈 */ public List midToAfter(List midList)throws EmptyStackException{ List afterList=new ArrayList(); Stack stack=new Stack(); for(String str:midList){ int flag=this.matchWitch(str); switch (flag) { case 7: afterList.add(str); break; case 1: stack.push(str); break; case 2: String pop=stack.pop(); while(!pop.equals("(")){ afterList.add(pop); pop=stack.pop(); } break; default: if(stack.isEmpty()){ stack.push(str); break; } else{ if(stack.peek().equals("(")){ stack.push(str); break; }else{ int ji1=this.youxianji(str); int ji2=this.youxianji(stack.peek()); if(ji1>ji2){ stack.push(str); }else{ while(!stack.isEmpty()){ String f=stack.peek(); if(f.equals("(")){ stack.push(str); break; }else{ if(this.youxianji(str)<=this.youxianji(f)){ afterList.add(f); stack.pop(); }else{ stack.push(str); break; } } } if(stack.isEmpty()){ stack.push(str); } } break; } } } } while(!stack.isEmpty()){ afterList.add(stack.pop()); } StringBuffer sb=new StringBuffer(); for(String s:afterList){ sb.append(s+" "); } //System.out.println(sb.toString()); return afterList; } /** 判断运算符的优先级 */ public int youxianji(String str){ int result=0; if(str.equals("+")||str.equals("-")){ result=1; }else{ result =2; } return result; } /** *判断字符串属于操作数、操作符还是括号 */ public int matchWitch(String s){ if(s.equals("(")){ return 1; }else if(s.equals(")")){ return 2; }else if(s.equals("+")){ return 3; }else if(s.equals("-")){ return 4; }else if(s.equals("*")){ return 5; }else if(s.equals("/")){ return 6; }else{ return 7; } } /** *计算a@b的简单方法 */ public Double singleEval(Double pop2,Double pop1,String str){ Double value=0.0; if(str.equals("+")){ value=pop2+pop1; }else if(str.equals("-")){ value=pop2-pop1; }else if(str.equals("*")){ value=pop2*pop1; }else { value=pop2/pop1; } return value; } private double result; public double getResult() { return result; } public void setResult(double result) { this.result = result; } private int state; public int getState() { return state; } public void setState(int state) { this.state = state; } public void countHouzhui(List list){ str = new StringBuilder(""); state=0; result=0; Stack stack=new Stack(); for(String str:list){ int flag=this.matchWitch(str); switch (flag) { case 3: case 4: case 5: case 6: Double pop1=stack.pop(); Double pop2=stack.pop(); Double value=this.singleEval(pop2, pop1, str); stack.push(value); break; default: Double push=Double.parseDouble(str); stack.push(push); break; } } if(stack.isEmpty()){ state=1; }else{ result=stack.peek(); str.append(stack.pop()); } } public void eval()throws Exception{ List list=new ArrayList(); //匹配运算符、括号、整数、小数，注意-和*要加\\ Pattern p = Pattern.compile("[+\\-/\\*()]|\\d+\\.?\\d*"); Matcher m = p.matcher(s1); while(m.find()){ list.add(m.group()); } List afterList=this.midToAfter(list); this.countHouzhui(afterList); } }} xml文件：
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