Android实现简单计算器源码

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<String> midToAfter(List<String> midList)throws EmptyStackException{            List<String> afterList=new ArrayList<String>();            Stack<String> stack=new Stack<String>();            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<String> list){            str = new StringBuilder("");            state=0;            result=0;            Stack<Double> stack=new Stack<Double>();            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<String> list=new ArrayList<String>();            //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<String> afterList=this.midToAfter(list);            this.countHouzhui(afterList);        }    }}

xml文件：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:background="#eef0ec"    tools:context="com.example.admin.caculator.MainActivity"    android:weightSum="1"    >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_weight="0.4"        android:background="#3f3c3c"        android:divider="@color/colorAccent"        android:showDividers="middle"        android:orientation="vertical">        <EditText            android:id="@+id/input"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_weight="4"            android:background="@null"            android:gravity="end"            android:inputType="none"            android:textColor="#ffffff"            android:textSize="24sp" />        <TextView            android:id="@+id/output"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_weight="6"            android:gravity="end"            android:textColor="#faf79b"            android:textSize="50sp" />    </LinearLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_weight="0.6"        android:orientation="vertical"        android:showDividers="middle"        android:divider="#0a0a0a">        <LinearLayout            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="0.2"            android:orientation="horizontal"            android:showDividers="middle"            android:divider="#0a0a0a">            <Button                android:id="@+id/txtClear"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="AC"                android:textColor="#d8169a"                android:textSize="20dp" />            <Button                android:id="@+id/txtDel"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="←"                android:textColor="#d8169a"                android:textSize="20dp" />            <Button                android:id="@+id/txtLeft"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="(" />            <Button                android:id="@+id/txtRight"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text=")" />            <Button                android:id="@+id/txtDiv"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="/"                android:textSize="20dp" />        </LinearLayout>        <LinearLayout            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="0.2"            android:orientation="horizontal"            android:showDividers="middle"            android:divider="#0a0a0a">            <Button                android:id="@+id/txt9"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="9"                android:textSize="20dp" />            <Button                android:id="@+id/txt8"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="8"                android:textSize="20dp" />            <Button                android:id="@+id/txt7"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="7"                android:textSize="20dp" />            <Button                android:id="@+id/txtMul"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="*"                android:textSize="20dp" />        </LinearLayout>        <LinearLayout            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="0.2"            android:orientation="horizontal"            android:showDividers="middle"            android:divider="#0a0a0a">            <Button                android:id="@+id/txt6"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="6"                android:textSize="20dp" />            <Button                android:id="@+id/txt5"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="5"                android:textSize="20dp" />            <Button                android:id="@+id/txt4"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="4"                android:textSize="20dp" />            <Button                android:id="@+id/txtPlus"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="+"                android:textSize="20dp" />        </LinearLayout>        <LinearLayout            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="0.2"            android:orientation="horizontal"            android:showDividers="middle"            android:divider="#0a0a0a">            <Button                android:id="@+id/txt1"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="1"                android:textSize="20dp" />            <Button                android:id="@+id/txt2"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="2"                android:textSize="20dp" />            <Button                android:id="@+id/txt3"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="3"                android:textSize="20dp" />            <Button                android:id="@+id/txtMinus"                android:layout_width="wrap_content"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="-"                android:textSize="20dp" />        </LinearLayout>        <LinearLayout            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_weight="0.2"            android:orientation="horizontal"            android:showDividers="middle"            android:divider="#0a0a0a">            <Button                android:id="@+id/txt0"                android:layout_width="0dp"                android:layout_height="match_parent"                android:layout_weight="2"                android:text="0"                android:textSize="20dp" />            <Button                android:id="@+id/txtDot"                android:layout_width="0dp"                android:layout_height="match_parent"                android:layout_weight="1"                android:text="."                android:textSize="20sp" />            <Button                android:id="@+id/txtIs"                style="@android:style/Widget.DeviceDefault.Button"                android:layout_width="0dp"                android:layout_height="match_parent"                android:layout_weight="1"                android:background="@color/colorAccent"                android:text="="                android:textSize="20dp"></Button>        </LinearLayout>    </LinearLayout></LinearLayout>