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基于Android实现计算器_android 计算器源代码 github

作者：2023面试高手 | 2024-03-12 08:33:20

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android 计算器源代码 github

最近发现我在CSDN里面分享的一些文件都被提高积分了，有的提高的有点夸张。所以以后我尽量把代码在博客里面贴全。

代码下载。

github地址：https://github.com/AtaoistPriest/Calculator

如果积分不够，复制以下代码也可以。当然欢迎积分下载。

这几天时间比较充裕，我用Android实现了一个计算器，以前也实现过，但那个版本功能简单，代码论乱，不易理解，关键是还有BUG。所以，我完善一下。实现计算器的难点主要是，输入算式时的排错和最后根据算术表达式求出数值。因为有括号，运算符优先级等问题，所以还是有点难度的。

计算器的界面如下：

好了，下面开始了。

界面布局文件：activity_main.xml

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3.     android:layout_width="wrap_content"
  4.     android:layout_height="wrap_content">
  5.     <TextView
  6.         android:layout_width="match_parent"
  7.         android:layout_height="wrap_content"
  8.         android:id="@+id/Equation"
  9.         android:textSize="16sp"
  10.         android:hint="输入算式进行计算"
  11.         android:layout_gravity="fill"
  12.         android:maxLines="4"
  13.         android:layout_marginTop="155sp"
  14.         android:layout_alignParentTop="true"
  15.         android:paddingRight="15sp"
  16.         android:layout_columnSpan="4"
  17.         android:gravity="right"/>
  18.     <TextView
  19.         android:layout_width="match_parent"
  20.         android:layout_height="wrap_content"
  21.         android:layout_below="@+id/Equation"
  22.         android:id="@+id/Result"
  23.         android:textSize="16sp"
  24.         android:hint="结果"
  25.         android:layout_gravity="fill"
  26.         android:maxLines="1"
  27.         android:layout_marginTop="20sp"
  28.         android:layout_marginBottom="15sp"
  29.         android:paddingRight="15sp"
  30.         android:layout_columnSpan="4"
  31.         android:gravity="right"/>
  32.     <GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
  33.         android:layout_width="match_parent"
  34.         android:layout_height="wrap_content"
  35.         android:layout_below="@+id/Result"
  36.         android:columnCount="4"
  37.         android:layout_gravity="center"
  38.         android:layout_marginLeft="13sp"
  39.         android:orientation="horizontal">
  40.         <Button
  41.             android:id="@+id/CE"
  42.             android:text="CE"
  43.             android:textSize="15sp"
  44.             android:layout_gravity="fill"
  45.             android:layout_marginTop="35sp"
  46.             android:layout_marginRight="5sp"
  47.             android:layout_marginBottom="5sp"
  48.             />
  49.         <Button
  50.             android:id="@+id/BACKSPACE"
  51.             android:text="BACKSPACE"
  52.             android:textSize="15sp"
  53.             android:layout_gravity="fill"
  54.             android:layout_marginTop="35sp"
  55.             android:layout_marginBottom="5sp"
  56.             android:layout_marginRight="5sp"
  57.             android:layout_columnSpan="2"
  58.             />
  59.         <Button
  60.             android:id="@+id/Remainder"
  61.             android:text="%"
  62.             android:textSize="15sp"
  63.             android:layout_marginTop="35sp"
  64.             android:layout_marginBottom="5sp"
  65.             />
  66.         <Button
  67.             android:id="@+id/Involution"
  68.             android:text="x^y"
  69.             android:textSize="15sp"
  70.             android:layout_marginBottom="5sp"
  71.             />
  72.         <Button
  73.             android:id="@+id/LBracket"
  74.             android:text="（"
  75.             android:textSize="15sp"
  76.             android:layout_marginBottom="5sp"
  77.             />
  78.         <Button
  79.             android:id="@+id/RBracket"
  80.             android:text="）"
  81.             android:textSize="15sp"
  82.             android:layout_marginBottom="5sp"
  83.             />
  84.         <Button
  85.             android:id="@+id/Factorial"
  86.             android:text="X!"
  87.             android:textSize="15sp"
  88.             android:layout_marginBottom="5sp"
  89.             />
  90.         <Button
  91.             android:id="@+id/Reciprocal"
  92.             android:text="1/X"
  93.             android:textSize="15sp"
  94.             android:layout_marginBottom="5sp"
  95.             />
  96.         <Button
  97.             android:id="@+id/P"
  98.             android:text="π"
  99.             android:textSize="15sp"
  100.             android:layout_marginBottom="5sp"
  101.             />
  102.         <Button
  103.             android:id="@+id/E"
  104.             android:text="e"
  105.             android:textSize="15sp"
  106.             android:layout_marginBottom="5sp"
  107.             />
  108.         <Button
  109.             android:id="@+id/Divide"
  110.             android:text="/"
  111.             android:textSize="15sp"
  112.             android:layout_marginBottom="5sp"
  113.             />
  114.         <Button
  115.             android:id="@+id/N7"
  116.             android:text="7"
  117.             android:textSize="15sp"
  118.             android:layout_marginRight="5sp"
  119.             android:layout_marginBottom="5sp"
  120.             />
  121.         <Button
  122.             android:id="@+id/N8"
  123.             android:text="8"
  124.             android:textSize="15sp"
  125.             android:layout_marginRight="5sp"
  126.             android:layout_marginBottom="5sp"
  127.             />
  128.         <Button
  129.             android:id="@+id/N9"
  130.             android:text="9"
  131.             android:textSize="15sp"
  132.             android:layout_marginRight="5sp"
  133.             android:layout_marginBottom="5sp"
  134.             />
  135.         <Button
  136.             android:id="@+id/Multiply"
  137.             android:text="*"
  138.             android:textSize="15sp"
  139.             android:layout_marginBottom="5sp"
  140.             />
  141.         <Button
  142.             android:id="@+id/N4"
  143.             android:text="4"
  144.             android:textSize="15sp"
  145.             android:layout_marginRight="5sp"
  146.             android:layout_marginBottom="5sp"
  147.             />
  148.         <Button
  149.             android:id="@+id/N5"
  150.             android:text="5"
  151.             android:textSize="15sp"
  152.             android:layout_marginRight="5sp"
  153.             android:layout_marginBottom="5sp"
  154.             />
  155.         <Button
  156.             android:id="@+id/N6"
  157.             android:text="6"
  158.             android:textSize="15sp"
  159.             android:layout_marginRight="5sp"
  160.             android:layout_marginBottom="5sp"
  161.             />
  162.         <Button
  163.             android:id="@+id/Subtract"
  164.             android:text="-"
  165.             android:textSize="15sp"
  166.             android:layout_marginBottom="5sp"
  167.             />
  168.         <Button
  169.             android:id="@+id/N1"
  170.             android:text="1"
  171.             android:textSize="15sp"
  172.             android:layout_marginRight="5sp"
  173.             android:layout_marginBottom="5sp"
  174.             />
  175.         <Button
  176.             android:id="@+id/N2"
  177.             android:text="2"
  178.             android:textSize="15sp"
  179.             android:layout_marginRight="5sp"
  180.             android:layout_marginBottom="5sp"
  181.             />
  182.         <Button
  183.             android:id="@+id/N3"
  184.             android:text="3"
  185.             android:textSize="15sp"
  186.             android:layout_marginRight="5sp"
  187.             android:layout_marginBottom="5sp"
  188.             />
  189.         <Button
  190.             android:id="@+id/Equal"
  191.             android:text="="
  192.             android:textSize="15sp"
  193.             android:layout_gravity="fill_vertical"
  194.             android:layout_height="wrap_content"
  195.             android:layout_width="wrap_content"
  196.             android:layout_rowSpan="2"
  197.             />
  198.         <Button
  199.             android:id="@+id/Zero"
  200.             android:text="0"
  201.             android:textSize="15sp"
  202.             android:layout_marginRight="5sp"
  203.             />
  204.         <Button
  205.             android:id="@+id/Point"
  206.             android:text="."
  207.             android:textSize="15sp"
  208.             android:layout_marginRight="5sp"
  209.             />
  210.         <Button
  211.             android:id="@+id/Add"
  212.             android:text="+"
  213.             android:textSize="15sp"
  214.             android:layout_marginRight="5sp"
  215.             />
  216.     </GridLayout>
  217. </RelativeLayout>
  218.  
  219.

接下来是程序入口MainActivity.java

  1. package com.example.ffy.orginal;
  2.  
  3. import android.app.Activity;
  4. import android.os.Bundle;
  5. import android.view.View;
  6. import android.widget.Button;
  7. import android.widget.TextView;
  8.  
  9. public class MainActivity extends Activity implements View.OnClickListener {
  10.  
  11.  
  12.     private TextView equationText,resultText;
  13.     private Button buttons[] = new Button[26];
  14.  
  15.     private CheckInput checkInput;
  16.     private CounterByEquation counterByEquation;
  17.  
  18.     //布局中所有按钮的ID
  19.     private int buttonIds[] = new int[]{
  20.             R.id.CE,R.id.BACKSPACE,R.id.Remainder,R.id.Involution,R.id.LBracket,R.id.RBracket,R.id.Factorial,
  21.             R.id.Reciprocal,R.id.P,R.id.E, R.id.Divide,R.id.N7,R.id.N8,R.id.N9,R.id.Multiply,R.id.N4,
  22.             R.id.N5,R.id.N6,R.id.Subtract,R.id.N1,R.id.N2,R.id.N3,R.id.Equal,R.id.Zero,R.id.Point, R.id.Add
  23.     };
  24.     //等式
  25.     private String equation = "";
  26.     @Override
  27.     protected void onCreate(Bundle savedInstanceState) {
  28.         super.onCreate(savedInstanceState);
  29.         setContentView(R.layout.activity_main);
  30.         init();  //初始化控件
  31.     }
  32.     /*
  33.     * 点击计算器键盘
  34.     *
  35.     * */
  36.     @Override
  37.     public void onClick(View v) {
  38.  
  39.         int id = v.getId();
  40.         Button button = (Button)findViewById(id);
  41.         String text = button.getText().toString();
  42.         switch (id){
  43.             /*
  44.             * 按数字按钮
  45.             * */
  46.             case R.id.N1:
  47.             case R.id.N2:
  48.             case R.id.N3:
  49.             case R.id.N4:
  50.             case R.id.N5:
  51.             case R.id.N6:
  52.             case R.id.N7:
  53.             case R.id.N8:
  54.             case R.id.N9:
  55.             case R.id.Zero:
  56.                 checkInput.setEquation(equation);
  57.                 if(checkInput.checkNumberInput()){
  58.                     equation = checkInput.getEquation();
  59.                     equation += text;
  60.                 }
  61.                 break;
  62.             /*
  63.             * 点击 + - * /
  64.             * */
  65.             case R.id.Add:
  66.             case R.id.Subtract:
  67.             case R.id.Multiply:
  68.             case R.id.Divide:
  69.                 checkInput.setEquation(equation);
  70.                 if(checkInput.checkOperationsInput()){
  71.                     equation = checkInput.getEquation();
  72.                     equation += text;
  73.                 }
  74.                 break;
  75.              /*
  76.              * 点击退格键
  77.              *
  78.              * */
  79.             case R.id.BACKSPACE:
  80.                 checkInput.setEquation(equation);
  81.                 checkInput.backSpace();
  82.                 equation = checkInput.getEquation();
  83.                 break;
  84.             /*
  85.             * 点击 x^y
  86.             * */
  87.             case R.id.Involution:
  88.                 checkInput.setEquation(equation);
  89.                 if(checkInput.checkInvolutionInput())
  90.                     equation+="^";
  91.                 break;
  92.             /*
  93.             * 倒数
  94.             * */
  95.             case R.id.Reciprocal:
  96.                 checkInput.setEquation(equation);
  97.                 if(checkInput.checkReciprocalInput())
  98.                     equation+="^(-1)";
  99.                 break;
  100.             /*
  101.             * 左括号
  102.             * */
  103.             case R.id.LBracket:
  104.                 checkInput.setEquation(equation);
  105.                 if(checkInput.checkLBracketInput())
  106.                     equation+="(";
  107.                 break;
  108.             /*
  109.             * 右括号
  110.             * */
  111.             case R.id.RBracket:
  112.                 checkInput.setEquation(equation);
  113.                 if(checkInput.checkRBracketInput())
  114.                     equation+=')';
  115.                 break;
  116.             /*
  117.             * 取余
  118.             * */
  119.             case R.id.Remainder:
  120.                 checkInput.setEquation(equation);
  121.                 if(checkInput.checkRemainderInput())
  122.                     equation+='%';
  123.                 break;
  124.             /*
  125.             * 求阶乘
  126.             * */
  127.             case R.id.Factorial:
  128.                 checkInput.setEquation(equation);
  129.                 if(checkInput.checkFactorialInput())
  130.                     equation+='!';
  131.                 break;
  132.             /*
  133.             * 清空按钮
  134.             * */
  135.             case R.id.CE:
  136.                 equation = "";
  137.                 resultText.setText("");
  138.                 break;
  139.             /*
  140.             * 小数点按钮
  141.             * */
  142.             case R.id.Point:
  143.                 checkInput.setEquation(equation);
  144.                 if(checkInput.checkPointInput()){
  145.                     equation = checkInput.getEquation();
  146.                     equation+=text;
  147.                 }
  148.                 break;
  149.             /*
  150.             * 点击π
  151.             * */
  152.             case R.id.P:
  153.                 checkInput.setEquation(equation);
  154.                 if (checkInput.checkSpecialSymbolBack()){
  155.                     equation+="π";
  156.                 }
  157.                 break;
  158.             /*
  159.             * 点击e
  160.             * */
  161.             case R.id.E:
  162.                 checkInput.setEquation(equation);
  163.                 if (checkInput.checkSpecialSymbolBack()){
  164.                     equation+="e";
  165.                 }
  166.                 break;
  167.             case R.id.Equal:
  168.                 resultText.setText(new CounterByEquation(equation).solveEquation());
  169.                 break;
  170.  
  171.         }
  172.         equationText.setText(equation);
  173.     }
  174.     /*
  175.     * init()初始化绑定所有的控件，并添加事件
  176.     * */
  177.     void init(){
  178.  
  179.         int length = buttons.length;
  180.         for(int i=0;i<length;i++){
  181.  
  182.             buttons[i] = (Button)findViewById(buttonIds[i]);
  183.             buttons[i].setOnClickListener(this);
  184.         }
  185.         equationText = (TextView)findViewById(R.id.Equation);
  186.         resultText = (TextView)findViewById(R.id.Result);
  187.         checkInput = new CheckInput();
  188.         counterByEquation = new CounterByEquation(equation);
  189.     }
  190. }

接下来是输入排错的功能，CheckInput.java.主要是加各种约束。

  1. package com.example.ffy.orginal;
  2.  
  3. public class CheckInput {
  4.  
  5.     private String equation;
  6.  
  7.  
  8.     public void setEquation(String equation){
  9.         this.equation = equation;
  10.     }
  11.  
  12.     public String getEquation(){
  13.         return equation;
  14.     }
  15.  
  16.     /*
  17.      * 检查特殊符号输入问题，π或e,类似1e,2e,3e这样的按照出错处理
  18.      * */
  19.     boolean checkSpecialSymbolBack(){
  20.  
  21.         int length = equation.length();
  22.         if(length==0) return true;
  23.         char perChar = equation.charAt(length-1); //获取前一位字符
  24.         if(perChar=='+'||perChar=='-'||perChar=='*'||perChar=='/') return true;
  25.         return false;
  26.     }
  27.  
  28.  
  29.  
  30.     /*
  31.      *  检查输入数字
  32.      * */
  33.     boolean checkNumberInput(){
  34.         int length = equation.length();
  35.         if(length==0) return true;
  36.         char perChar = equation.charAt(length-1);
  37.         //避免出现  π1,e1,)1现象
  38.         if(perChar=='π'||perChar=='e'||perChar==')'||perChar=='!') return false;
  39.         //避免出现01,+001,2^00002等现象
  40.         if(length==1&&perChar=='0') equation = "";
  41.         if(length>1){
  42.             char perPerChar = equation.charAt(length-2);
  43.             if((perPerChar=='+'||perPerChar=='-'||perPerChar=='*'||perPerChar=='/'||perPerChar=='^')&&perChar=='0'){
  44.                 equation = equation.substring(0,length-1);
  45.             }
  46.         }
  47.         return true;
  48.     }
  49.  
  50.  
  51.     /*
  52.      *小数点输入检查
  53.      * */
  54.     boolean checkPointInput(){
  55.  
  56.         int length = equation.length();
  57.         //自动补0
  58.         if(length==0) equation+="0";
  59.         char perChar = equation.charAt(length-1);
  60.         //自动补0
  61.         if(perChar=='+'||perChar=='-'||perChar=='*'||perChar=='/'||perChar=='%') equation+="0";
  62.         if(perChar=='π'||perChar=='e'||perChar==')'||perChar=='('||perChar=='^'||perChar=='!') return false;
  63.         int pointNum = 0;
  64.         for(int i = length-1;i>=0;i--){
  65.             char checkChar = equation.charAt(i);
  66.             if(checkChar=='.') pointNum++;
  67.             if(checkChar=='^') return false;
  68.             if(checkChar=='+'||checkChar=='-'||checkChar=='*'||checkChar=='/'||checkChar=='%') break;
  69.         }
  70.         if(pointNum>0) return false;
  71.         return true;
  72.     }
  73.     /*
  74.      * 输入+ - * / 时进行检查，在他们的前面不能有 .和%
  75.      * */
  76.     boolean checkOperationsInput(){
  77.         int length = equation.length();
  78.         if(length==0) return false;
  79.         char perChar = equation.charAt(length-1);
  80.         if(perChar=='%'||perChar=='.'||perChar=='^'||perChar=='!'||perChar=='(') return false;
  81.         //替换
  82.         if(perChar=='+'||perChar=='-'||perChar=='*'||perChar=='/')
  83.             equation = equation.substring(0,length-1);
  84.         return true;
  85.     }
  86.     /*
  87.      * 退格处理
  88.      * */
  89.     void backSpace(){
  90.  
  91.         int length = equation.length();
  92.         if(length==0) return;
  93.         char charPer = equation.charAt(length-1);
  94.         equation = equation.substring(0,length-1);
  95.     }
  96.     /*
  97.      * 检查 x^y
  98.      * */
  99.     boolean checkInvolutionInput(){
  100.  
  101.         int length = equation.length();
  102.         if(length==0) return false;
  103.         char perChar = equation.charAt(length-1);
  104.         if(perChar!='1'&&perChar!='2'&&perChar!='3'&&perChar!='4'&&perChar!='5'&&perChar!='6'&&perChar!='7'
  105.                 &&perChar!='8'&&perChar!='9'&&perChar!=')'&&perChar!='e'&&perChar!='π'&&perChar!='0') return false;
  106.         //一个式子里只能有 ^
  107.         int iNum = 0;
  108.         for(int i = length-1;i>0;i--){
  109.             char iChar = equation.charAt(i);
  110.             if(iChar=='^') iNum++;
  111.             if (iChar=='+'||iChar=='-'||iChar=='*'||iChar=='/'||iChar=='%') break;
  112.         }
  113.         if(iNum>0) return false;
  114.         return true;
  115.     }
  116.     /*
  117.      * 倒数
  118.      * */
  119.     boolean checkReciprocalInput(){
  120.         int length = equation.length();
  121.         if(length==0) return false;
  122.         char perChar = equation.charAt(length-1);
  123.         if(perChar!='1'&&perChar!='2'&&perChar!='3'&&perChar!='4'&&perChar!='5'&&perChar!='6'&&perChar!='7'
  124.                 &&perChar!='8'&&perChar!='9'&&perChar!=')'&&perChar!='0') return false;
  125.         //单独一个0不能求倒数
  126.         int iNum = 0;
  127.         for(int i = length-1;i>=0;i--){
  128.             char iChar = equation.charAt(i);
  129.             iNum++;
  130.             if (iChar=='+'||iChar=='-'||iChar=='*'||iChar=='/'||iChar=='%') break;
  131.         }
  132.         if(iNum==1&&perChar=='0') return false;
  133.         return true;
  134.     }
  135.     /*
  136.      * 输入左括号
  137.      * */
  138.     boolean checkLBracketInput(){
  139.         int length = equation.length();
  140.         if(length==0) return true;
  141.         char perChar = equation.charAt(length-1);
  142.         if(perChar=='+'||perChar=='-'||perChar=='*'||perChar=='/'||perChar=='%'||perChar=='^'||perChar=='(') return true;
  143.         return false;
  144.     }
  145.     /*
  146.      * 输入右括号
  147.      * */
  148.     boolean checkRBracketInput(){
  149.         int length = equation.length();
  150.         if(length==0) return false;
  151.         char perChar = equation.charAt(length-1);
  152.         //左右符号要匹配
  153.         int lNum = 0,rNum = 0;
  154.         for(int i = length-1;i>=0;i--){
  155.             char checkChar = equation.charAt(i);
  156.             if(checkChar=='(') lNum++;
  157.             if(checkChar==')') rNum++;
  158.             if(lNum-rNum==1) break;
  159.         }
  160.         if((lNum-rNum==1)&&(perChar=='1'||perChar=='2'||perChar=='3'||perChar=='4'||perChar=='5'||perChar=='6'||perChar=='7'
  161.                 ||perChar=='8'||perChar=='9'||perChar=='0'||perChar==')')) return true;
  162.         return false;
  163.     }
  164.     /*
  165.      *  取余
  166.      * */
  167.     boolean checkRemainderInput(){
  168.         int length = equation.length();
  169.         if(length==0) return false;
  170.         char perChar = equation.charAt(length-1);
  171.         if(perChar=='1'||perChar=='2'||perChar=='3'||perChar=='4'||perChar=='5'||perChar=='6'||perChar=='7'
  172.                 ||perChar=='8'||perChar=='9'||perChar==')') return true;
  173.  
  174.         return false;
  175.     }
  176.     /*
  177.      * 求阶乘
  178.      * */
  179.     boolean checkFactorialInput(){
  180.         int length = equation.length();
  181.         if(length==0) return false;
  182.         char perChar = equation.charAt(length-1);
  183.         if(perChar=='!'||perChar=='%'||perChar=='^'||perChar=='('||perChar=='+'
  184.                 ||perChar=='-'||perChar=='*'||perChar=='/') return false;
  185.         //小数点阶乘不可以存在
  186.         for(int i=length-1;i>=0;i--){
  187.             char checkChar = equation.charAt(i);
  188.             if(checkChar=='.') return false;
  189.             if(checkChar=='+'||checkChar=='-'||checkChar=='*'||checkChar=='/') break;
  190.         }
  191.         return true;
  192.     }
  193. }

最后是根据算术表达式求出最终结果。主要思路是，先转换为后缀表达式，再根据后缀表达式求值。CounterByEquation.java

  1. package com.example.ffy.orginal;
  2.  
  3. import android.util.Log;
  4.  
  5. import java.util.Stack;
  6. import java.util.Queue;
  7.  
  8.  
  9. public class CounterByEquation {
  10.  
  11.     private String equation;
  12.  
  13.     private Stack<String> stack;  //存储符号
  14.     private String []queue = new String[50];  //接受中缀表达式
  15.     private int count=0;
  16.  
  17.  
  18.     public CounterByEquation(String equation){
  19.         this.equation = equation;
  20.     }
  21.  
  22.     /*
  23.     *           (  )   * - / +  ^  !  x^(-1)  %  e  π   3.11 5
  24.     *
  25.     *           ((3^5)+5^(-1)+((6%4)+e)*6)*2
  26.     *           3^5 5^-1 + 6%4 e + 6 * +
  27.     * */
  28.     String solveEquation(){
  29.  
  30.         int length = equation.length();
  31.  
  32.         /*
  33.         * 由中缀表达式求后缀表达式
  34.         * */
  35.         stack = new Stack<>();
  36.  
  37.         for(int i=0;i<length;i++){
  38.  
  39.             char curChar = equation.charAt(i);
  40.             if(curChar=='('||curChar=='+'||curChar=='-'||curChar=='*'||curChar=='/'||curChar=='%'||curChar=='^'){
  41.  
  42.                 String top = "";
  43.                 if(!stack.empty())
  44.                     top = stack.peek();
  45.                 if(curChar=='(')  {
  46.                     stack.push(curChar+"");
  47.                 } else if (curChar == '%' || curChar == '^') {
  48.                     if(!stack.empty()&&(top.equals("^")||top.equals("%"))){
  49.                         queue[count++] = stack.pop();
  50.                     }
  51.                     stack.push(curChar+"");
  52.  
  53.                 } else if ((curChar == '+' || curChar == '-')) {
  54.                     while (true) {
  55.                         if (stack.empty()) break;
  56.                         if (stack.peek().equals("(")) break;
  57.                         queue[count++] = stack.pop();
  58.                     }
  59.                     stack.push(curChar+"");
  60.                 } else if (curChar == '*' || curChar == '/') {
  61.                     if (!stack.empty()){
  62.                         while (true) {
  63.                             if (stack.peek().equals("*") || stack.peek().equals("/") || stack.peek().equals("%") || stack.peek().equals("^")) {
  64.                                 queue[count++] = stack.pop();
  65.                             }else{
  66.                                 break;
  67.                             }
  68.                             if (stack.empty()) break;
  69.                             if (stack.peek().equals("(")) break;
  70.                         }
  71.                     }
  72.                     stack.push(curChar+"");
  73.                 }
  74.             }
  75.             else if (curChar==')'){
  76.                 while(true){
  77.                     String tmp = stack.pop();
  78.                     if(tmp.equals("(")) break;
  79.                     else queue[count++] = tmp;
  80.                 }
  81.             }
  82.             else{  //数字
  83.                 String numStr = curChar+"";
  84.                 for(i++;i<length;i++)
  85.                 {
  86.                     char curBackChar = equation.charAt(i);
  87.                     if(curBackChar==')'||curBackChar=='+'||curBackChar=='-'||curBackChar=='*'||curBackChar=='/'||curBackChar=='%'||curBackChar=='^'){
  88.                         i--;
  89.                         break;
  90.                     }
  91.                     else
  92.                         numStr+=curBackChar;
  93.                 }
  94.                 queue[count++] = numStr;
  95.  
  96.             }
  97.         }
  98.  
  99.         while(true){
  100.             if(stack.empty()) break;
  101.             queue[count++] = stack.pop();
  102.         }
  103.         String logStr = "";
  104.         for(int i=0;i<count;i++){
  105.             logStr+=queue[i]+" ";
  106.         }
  107.         Log.e("ERROR!!!!!!!!!!!!",logStr);
  108.  
  109.         /*由中缀表达式求值*/
  110.         for(int i=0;i<count;i++){
  111.             String member = queue[i];
  112.             int numLength = member.length();
  113.             if(member.charAt(numLength-1)=='!'){
  114.                 member = member.substring(0,numLength-1);
  115.                 int num = Integer.parseInt(member);
  116.                 int sum = 1;
  117.                 while(num>0){
  118.                     sum *= (num--);
  119.                 }
  120.                 queue[i] = sum+"";
  121.                 continue;
  122.             }
  123.             if(member.equals("π")) {
  124.                 queue[i] = "3.1415926";
  125.                 continue;
  126.             }
  127.             if(member.equals("e")) {
  128.                 queue[i] = "2.71828183";
  129.                 continue;
  130.             }
  131.  
  132.             if(member.equals("+")||member.equals("-")||member.equals("*")||member.equals("/")||member.equals("%")||member.equals("^")){
  133.                 double first = Double.parseDouble(queue[i-2]);
  134.                 double second = 0;
  135.                 if(!queue[i-1].equals("-"))
  136.                     second = Double.parseDouble(queue[i-1]);
  137.                 if (member.equals("+")) first += second;
  138.                 if (member.equals("-")){
  139.                     //处理  x^(-1)的情况
  140.                     if(queue[i+1]!=null&&queue[i+1].equals("^")){
  141.                         first = 1 / first;
  142.                         //为了不影响接下来的运算，在数组去除^
  143.                         for(int j = i+1;j<count-1;j++)
  144.                             queue[j] = queue[j+1];
  145.                         count--;
  146.                     }else{
  147.                         first -= second;
  148.                     }
  149.                 }
  150.                 if (member.equals("*")) first *= second;
  151.                 if (member.equals("/")) first /= second;
  152.                 if (member.equals("%")) first %= second;
  153.                 if (member.equals("^")){
  154.                     double sum = 1;
  155.                     for(int j = (int)second;j>0;j--){
  156.                         sum*=first;
  157.                     }
  158.                     first = sum;
  159.                 }
  160.                 queue[i-2] = first+"";
  161.                 //前移
  162.                 for(int j = i-1;j<count-2;j++){
  163.                     queue[j] = queue[j+2];
  164.                 }
  165.                 count-=2;
  166.                 i-=2;
  167.             }
  168.         }
  169.         return queue[0];
  170.     }
  171.  
  172. }

 

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