小学四则运算APP 第三阶段冲刺

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:scrollbars="vertical"
    android:paddingBottom="10dp"
    android:paddingTop="5dp"
    android:background="@drawable/b1">
	<LinearLayout 
	    android:layout_width="fill_parent"
	    android:layout_height="fill_parent"
	    android:orientation="vertical" 
	    android:paddingLeft="8dp"
	    android:paddingRight="8dp">
	    <RelativeLayout 
	        android:layout_width="fill_parent"
	        android:layout_height="fill_parent">
	        <EditText
			    android:id="@+id/editText"
			    android:layout_width="fill_parent"
			    android:layout_height="90dp"
			    android:autoText="true"
			    android:hint="@string/editText_hint_text"
			    android:minHeight="60dp"
			    android:background="@drawable/selector"
			    android:paddingTop="10dp"
			    android:paddingBottom="15dp" 
			    android:singleLine="false"
			    android:scrollbars="vertical"/>
	        <TextView 
	            android:id="@+id/tv"
	            android:layout_alignRight="@id/editText"
	            android:layout_alignBottom="@id/editText"
	            android:layout_width="wrap_content"
	        	android:layout_height="wrap_content"
	        	android:text="@string/kong"
	        	android:textColor="#CD0000"/>
	    </RelativeLayout>
		<LinearLayout
		    android:layout_width="fill_parent"
		    android:layout_height="fill_parent"
		    android:orientation="horizontal"
		    android:paddingTop="10dip"
		    android:paddingBottom="5dp" >
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="("
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/left"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text=")"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/right"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"
		            />
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="Clean"
		            android:layout_weight="1"
		            android:background="@drawable/selector"
		            android:id="@+id/ac"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"
		           />
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="Backspace"
		            android:layout_weight="1"
		            android:background="@drawable/selector"
		            android:id="@+id/bs"
		            android:textStyle="bold"
		           
		           />
		        
		</LinearLayout>
		<LinearLayout 
		    android:layout_width="fill_parent"
		    android:layout_height="wrap_content"
		    android:orientation="horizontal"
		    android:paddingBottom="5dp">
		   
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="7"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
					android:id="@+id/num7"
					android:textStyle="bold"
					android:layout_marginRight="5dp"/>	            
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="8"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/num8"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="9"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/num9"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="÷"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/divide"
		            android:textStyle="bold"
		           />
		</LinearLayout>
	<LinearLayout 
		    android:layout_width="fill_parent"
		    android:layout_height="fill_parent"
		    android:orientation="horizontal"
		    android:layout_weight="1"
		    android:paddingBottom="5dp">
		   
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="4"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/num4"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="5"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/num5"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="6"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/num6"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="×"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/mul"
		            android:textStyle="bold"
		            />
		</LinearLayout>
		<LinearLayout 
		    android:layout_width="fill_parent"
		    android:layout_height="fill_parent"
		    android:orientation="horizontal"
		    android:layout_weight="1"
		    android:paddingBottom="5dp">
		   
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="1"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/num1"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="2"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/num2"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="3"
		            android:layout_weight="1"
		            android:background="@drawable/selector"
		            android:textSize="30sp"
		            android:id="@+id/num3"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="－"
		            android:textSize="35sp"
		            android:layout_weight="1"
		            android:background="@drawable/selector"
		            android:id="@+id/sub"
		            android:textStyle="bold"
		            />
		</LinearLayout>
	<LinearLayout 
		    android:layout_width="fill_parent"
		    android:layout_height="fill_parent"
		    android:orientation="horizontal"
		    android:layout_weight="1"
		    android:paddingBottom="5dp"
		   >
		   
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="0"
		            android:layout_weight="1"
		            android:textSize="30sp"
		        	android:background="@drawable/selector"
		        	android:id="@+id/num0"
		        	android:textStyle="bold"
		        	android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="."
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/pot"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="fill_parent"
		            android:text="+"
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/add"
		            android:textStyle="bold"
		            android:layout_marginRight="5dp"/>
		        <Button 
		            android:layout_width="fill_parent"
		            android:layout_height="wrap_content"
		            android:text="="
		            android:layout_weight="1"
		            android:textSize="30sp"
		            android:background="@drawable/selector"
		            android:id="@+id/equ"
		            android:textStyle="bold"
		           />		    
		</LinearLayout>
		<LinearLayout 
		    android:layout_width="fill_parent"
		    android:layout_height="fill_parent"
		    android:orientation="horizontal"
		    android:layout_weight="1"
		    android:paddingBottom="5dp">
			<Button 
			    android:id="@+id/minus"
		        android:layout_width="fill_parent"
		        android:layout_height="fill_parent"
		        android:text="+/-"
		        android:layout_weight="1"
		        android:textSize="30sp"
		        android:background="@drawable/selector"
		        android:textStyle="bold"
		        android:layout_marginRight="5dp"/>	
   
	  </LinearLayout>
	</LinearLayout>
</ScrollView>

　Calculator.java

package com.manymore13.calc;

import java.math.BigDecimal;
import java.util.EmptyStackException;
import java.util.Stack;

import android.util.Log;

// 测试匹配否
// 特殊加减乘除 ＋ － × ÷     
// 特殊正负 ﹢﹣
// 普通加减乘除正负 + - * / + -
public class Calculator {

    private static String expression;
    
    
    // 后缀式
    private String suffix;

    // 特殊左括号
    final static char LEFT_NORMAL = '﹙';
    // 特殊右括号
    final static char RIGHT_NORMAL = '﹚';
    // 特殊负号
    final static char MINUS = '﹣';
    // 特殊加号
    final static char ADD = '＋';
    // 特殊乘法
    final static char MUL = '×';
    // 特殊除法
    final static char DIV = '÷';
    // 特殊减法
    final static char SUB = '－';
    // 特殊等于号
    final static char equ = '＝';
    
    public static String getExpression() {
        return expression;
    }

    
    
    // 返回后缀
    public String getSuffix() {
        return suffix;
    }

    public void setExpression(String equation) {
        expression = equation;
        createSuffix();
        
    }
    
    public Calculator(String equation)
    {
        expression = equation;
        createSuffix();
    }
    
    public Calculator()
    {
        expression = "";
        suffix = "";
    }
    
    /**
     *  判断括号有没有匹配
     *  匹配方法：遇到左括号进栈，遇到右括号出栈并且比对出栈的括号
     * 
     */
    public  boolean isBalanced()
    {
                        
        Stack<Character> store = new Stack<Character>();
        store.clear();
        char c;
        for(int i=0; i<expression.length(); i++)
        {
            c = expression.charAt(i);
            switch(c)
            {
                
                case LEFT_NORMAL:
                {
                    store.push(expression.charAt(i));
                    break;
                }
                case RIGHT_NORMAL:
                {    
                    if(store.isEmpty() || store.pop()!= LEFT_NORMAL)
                    {
                        return false;
                    }
                    break;
                    
                }
                                        
            }
        }
        if(store.isEmpty())
        {
            return true;
        }
        else
        {
            return false;
        }
        
    }
    

    private static boolean isOperator(char ope)
    {
        if(ope == ADD || ope==SUB 
                ||ope == MUL || ope == DIV)
        {
            return true;
        }
        return false;
    }
    
    private static boolean isNum(char c)
    {
        if(c>='0' && c<='9')
        {
            return true;
        }
        return false;
    }
    // 中缀式转后缀式
    public  String createSuffix()
    {
        Stack<String> stack = new Stack<String>();
        String exp = expression.trim();
        String suf = "";
        int i = 0;
        char c;
        while(i < exp.length())
        {
            c = exp.charAt(i);
            if(c == LEFT_NORMAL) // 左括号
            {
                stack.push(LEFT_NORMAL+"");
            }
            else if(isFit(c)) // 符合数字的一部分
            {
                String num = "";
                
                while(i<exp.length() && isFit(exp.charAt(i)) )
                {
                    
                    num+=exp.charAt(i);
                    i++;
                }
                suf += (num + " "); //后缀
                i--;
            }else if(c == ADD || c == SUB || c == MUL ||c == DIV)  // 运算符
            {
                while(true)
                {
                    if(stack.isEmpty())
                    {
                        break;
                    }
                    if(stack.peek().equals(""+LEFT_NORMAL))
                    {
                        break;
                    }
                    if(compare(stack.peek().charAt(0),c))
                    {
                        break;
                    }
                    suf += (stack.pop()+" "); // 后缀
                }
                stack.push(c+""); 
            }
            else if(c == RIGHT_NORMAL)
            {
                while(!stack.isEmpty())
                {
                    if(stack.peek().equals(""+LEFT_NORMAL))
                    {
                        stack.pop();
                        break;
                    }
                    suf += (stack.pop() + " "); // 后缀
                }
                
            }
            i++;
            
        }
        while(!stack.isEmpty())
        {
            suf += (stack.pop() + " "); // 后缀
        }
        this.suffix = suf;
        return suf;
        
    }
    
    /**
     *  判断是否符合数字的一部分
     * @param digit
     * @return 符合返回true 否则返回false
     */
    private boolean isFit(char digit)
    {
        if(digit>='0' && digit<='9'||digit ==MINUS||digit=='.' )
        {
            return true;
        }
        return false;
    }
    
    // 栈中运算符与将要读取的运算符作比较
    // 返回true指示栈中运算符优先级大于将要读取运算符
    // 其他的低于或等于都返回false
    private boolean compare(char stackOpe, char nextOpe)
    {
        int v1 = value(stackOpe);
        int v2 = value(nextOpe);
        if( v1 < v2)
        {
            return true;
        }
        return false;
    }
    
    // 运算符优先级
    private int value(char ope)
    {
        if(ope==ADD || ope==SUB)
        {
            return 1;
        }    
        else if(ope==MUL || ope==DIV)
        {
            return 2;
        }
        else
        {
            return 0;
        }
    }
    
    /**
     * @param suffix 后缀式
     * @return 利用后缀式算出结果
     */
    public String getResult()
    {
        suffix = suffix.replace(MINUS, '-');
        String[] str = suffix.split(" ");
        Stack<String> valueStack = new Stack<String>();
        for(int i=0; i<str.length; i++)
        {
            // 遇到运算符出栈
            if(str[i].equals(ADD+"") || str[i].equals(SUB+"")
                || str[i].equals(MUL+"") || str[i].equals(DIV+""))
            {
                String rightNum;
                String leftNum; 
                try
                {
                    rightNum = valueStack.pop();
                    leftNum = valueStack.pop();
                    String result = calc(leftNum,rightNum,str[i]);
                    valueStack.push(result);
                }catch(EmptyStackException empty)
                {
                    return "算式出现异常";
                }
                
                
            }
            else
            {
                // 遇到数字进栈
                valueStack.push(str[i]);
            }
        }
        if(!valueStack.isEmpty())
        {
            return valueStack.pop();
        }
        return "栈为空 ，出现错误！";
    }
    
    public static String calc(String leftNum, String rightNum, String ope)
    {
        BigDecimal bigLeftNum = null;
        BigDecimal bigRightnum = null;
        try
        {
            bigLeftNum = new BigDecimal(leftNum);
            bigRightnum = new BigDecimal(rightNum);
        }catch(NumberFormatException e)
        {
            return "算式出现异常";
        }
        switch(ope.charAt(0))
        {
            // 处理加法
            case ADD:return  bigLeftNum.add(bigRightnum).toString();
            // 处理减法
            case SUB:return  bigLeftNum.subtract(bigRightnum).toString();
            // 处理乘法
            case MUL:return  bigLeftNum.multiply(bigRightnum).toString();
            // 处理乘法
            case DIV:
                {
                    if(bigRightnum.doubleValue()==0)
                    {
                        return "除数为零";
                    }
                    // 20为小数点后的位数
                    String result = bigLeftNum.divide(bigRightnum,20,BigDecimal.ROUND_DOWN).toString();
                    int mark = 0;
                    if( (mark = result.indexOf('.'))!=-1)
                    {
                        for(int i=mark; i<result.length(); i++)
                        {
                            if(result.charAt(i)!='0')
                            {
                                mark = i;
                            }
                        }
                        Log.d("mark--1 :", mark+"");
                        if(result.charAt(mark)=='.')
                        {
                            mark -= 1;
                        }
                        Log.d("mark--2 :", mark+"");
                        
                        Log.d("result", result.substring(0,mark+1));
                        result = result.substring(0,mark+1);
                        return result;
                    }
                    else
                    {
                        return result;
                    }
                    
                }
        }
        return null;
    }
    
    
    
    // 测试括号匹配 - —
    public static void main(String[] s)
    {
        String str1 = "﹙5.3＋3﹚×﹙3＋8﹚";
        String str2 = "[{}]{}";
        String str3 = "({}{})";
        String str4 = "16.2+(6.72-4.25)-3.72";
        String str5 = "(((10+7)*(20/30))-(2*40))";
        String str6 = "12";
        
        Calculator cal = new Calculator(str1);
        System.out.println("匹配："+cal.isBalanced());
        System.out.println("后缀："+cal.getSuffix());
        String reult = cal.getResult();
        System.out.println("结果: "+reult);
        
    }
}

MycalcActivity.java

package com.manymore13.calc;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnFocusChangeListener;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MyCalcActivity extends Activity {
    
    AlertDialog.Builder  mBuilder ; 
    private List<Button> buttonList = new ArrayList<Button>(25); 
    private Button[] num = new Button[10];
    private Calculator cal = new Calculator();
    private TextView tviewPrompt; 
    private boolean legal = true;
    int[] Idnum = new int[]
            {
                R.id.num0,
                R.id.num1,
                R.id.num2,
                R.id.num3,
                R.id.num4,
                R.id.num5,
                R.id.num6,
                R.id.num7,
                R.id.num8,
                R.id.num9
            }; 
    private static EditText edit;
    private Button btnAdd;
    private Button btnSub;
    private Button btnMul;
    private Button btnDiv;
    private Button btnPot;
    private Button btnEqu;
    private Button btnBC;
    private Button btnAC;
    private Button btnLeft;
    private Button btnRight;
    private Button btnMinus; // 负号
    
    private Button btnMoveLeft;
    private Button btnMoveRight;
    public static EditText getEdit()
    {
        return edit;
    }
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        this.findView();
     
        
        // 屏蔽软键盘 这样做有个弊端，就是不能自动换行
//      edit.setInputType(InputType.TYPE_NULL);
//      edit.setInputType(InputType.TYPE_DATETIME_VARIATION_NORMAL);
        
        
        edit.addTextChangedListener(new TextWatcher() {
            String str;
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                str = s.toString();
                cal.setExpression(str);

                if(str.equals("")||(str.indexOf(Calculator.LEFT_NORMAL)==-1
                        &&str.indexOf(Calculator.RIGHT_NORMAL)==-1))
                {
                    legal = true;
                    tviewPrompt.setText(R.string.kong);
                }else if(cal.isBalanced())
                {
                    System.out.println(cal.isBalanced());
                    legal = true;
                    tviewPrompt.setText(R.string.legal);
                }else
                {
                    legal = false;
                    tviewPrompt.setText(R.string.wrongful);
                }
                
            }
            
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {                
            }
            
            @Override
            public void afterTextChanged(Editable s) {
                
                
            }
        });
        for(Button current:buttonList)
        {
            System.out.println(current.getText());
            current.setOnClickListener(new btnOnclickListtenner());
        }
        
        // 屏蔽软键盘
        edit.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                
                InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
                imm.hideSoftInputFromWindow(edit.getWindowToken(), 0);
                edit.setBackgroundColor(0x7f48D1CC);
                
            }
        });
        
        edit.setOnFocusChangeListener(new OnFocusChangeListener() {
            
            @Override
            public void onFocusChange(View v, boolean hasFocus) {
                InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
                imm.hideSoftInputFromWindow(edit.getWindowToken(), 0);
                edit.setBackgroundColor(0x7f48D1CC);
                
            }
        });
        
    }
    
    
    
    
   public void findView()
   {
       // 获取算式框的实例
       edit = (EditText)findViewById(R.id.editText);
       // 获取数字按钮的实例
       for(int i=0; i<=9; i++)
       {
           num[i] = (Button)findViewById(Idnum[i]);
       }
       
       tviewPrompt = (TextView)findViewById(R.id.tv);
       Collections.addAll(buttonList, num);
       
       btnAdd = (Button)findViewById(R.id.add);
       Collections.addAll(buttonList,btnAdd);
       
       btnSub = (Button)findViewById(R.id.sub);
       Collections.addAll(buttonList,btnSub);
       
       btnMul = (Button)findViewById(R.id.mul);
       Collections.addAll(buttonList,btnMul);
       
       btnDiv = (Button)findViewById(R.id.divide);
       Collections.addAll(buttonList,btnDiv);
       
       btnPot = (Button)findViewById(R.id.pot);
       Collections.addAll(buttonList,btnPot);
       
       btnEqu = (Button)findViewById(R.id.equ);
       Collections.addAll(buttonList,btnEqu);
       
       btnBC  = (Button)findViewById(R.id.bs);
       Collections.addAll(buttonList,btnBC);
       
       btnAC  = (Button)findViewById(R.id.ac);
       Collections.addAll(buttonList,btnAC);
       
       btnLeft = (Button)findViewById(R.id.left);
       Collections.addAll(buttonList, btnLeft);
       
       btnRight = (Button)findViewById(R.id.right);
       Collections.addAll(buttonList, btnRight);
       
       btnMinus = (Button)findViewById(R.id.minus);
       Collections.addAll(buttonList, btnMinus);
       
      
   }
   
   class btnOnclickListtenner implements OnClickListener
   {
      
        @Override
        public void onClick(View v) 
        {
            // 获取EditText的编辑版
            Editable edtTable = edit.getText();
            
            // 获取光标位置
            int where = edit.getSelectionStart();
            String inputData = "";
            switch(v.getId())
            {
                case R.id.num0:
                {
                    inputData = "0";
                    break;
                }
                case R.id.num1:
                {
                    inputData = "1";
                    break;
                }
                case R.id.num2:
                {
                    inputData = "2";
                    break;
                }
                case R.id.num3:
                {
                    inputData = "3";
                    break;
                }
                case R.id.num4:
                {
                    inputData = "4";
                    break;
                }
                case R.id.num5:
                {
                    inputData = "5";
                    break;
                }
                case R.id.num6:
                {
                    inputData = "6";
                    break;
                }
                case R.id.num7:
                {
                    inputData = "7";
                    break;
                }
                case R.id.num8:
                {
                    inputData = "8";
                    break;
                }
                case R.id.num9:
                {
                    inputData = "9";
                    break;
                }
                // 全部清除
                case R.id.ac:
                {
                    inputData = "";
                    edit.setText("");
                }
                // 退格键
                case R.id.bs:
                {
                    if(where >0)
                    {
                        edtTable.delete(where-1, where);
                    }
                    break;
                }
                case R.id.add:
                {
                    inputData = Calculator.ADD+"";
                    break;
                }
                case R.id.sub:
                {
                    inputData = Calculator.SUB+"";
                    break;
                }
                case R.id.mul:
                {
                    inputData = Calculator.MUL+"";
                    break;
                }
                case R.id.divide:
                {
                    inputData = Calculator.DIV+"";
                    break;
                }
                case R.id.pot:
                {
                    inputData = ".";
                    break;
                }
                case R.id.left:
                {
                    inputData = Calculator.LEFT_NORMAL+"";
                    break;
                }
                case R.id.right:
                {
                    inputData = Calculator.RIGHT_NORMAL+"";
                    break;
                }
                case R.id.minus:
                {
                    inputData = Calculator.MINUS+"";
                    break;
                }
                // 处理光标左移
                
                //处理等于
                case R.id.equ:
                {
                    
                    inputData = "";
                    String str = edtTable.toString();
                    where = str.length();
                    if(checkLegal(str))
                    {
                        cal.setExpression(edtTable.toString());
                        String result = cal.getResult();
                        inputData = "
"+Calculator.equ+result;
                        
                    }
                    break;
                    
                }
            }
            
            edtTable.insert(where, inputData);
        }
        // 检查运算式是否合格
        public boolean checkLegal(String exp)
        {
            if( (legal && (!exp.equals(""))&&(exp.indexOf(Calculator.equ)==-1))
                    &&(exp.indexOf(Calculator.ADD)!=-1 ||exp.indexOf(Calculator.SUB)!=-1
                     ||exp.indexOf(Calculator.MUL)!=-1 ||exp.indexOf(Calculator.DIV)!=-1))
            {
                return true;
            }
            return false;
        }
           
   }
   
   public boolean onCreateOptionsMenu(Menu menu)  
   {  
       menu.add(0,1,0,"关于");  
       menu.add(1,2,1,"退出");  
       return true;   // 这里要返回true 否则菜单不显示  
   }      
    @Override
    public boolean onOptionsItemSelected(MenuItem item) 
    {
        mBuilder = new AlertDialog.Builder(this); 
    
        if(item.getItemId()==1)
        {
            mBuilder.setMessage(R.string.abount).setTitle("关 于").show().setInverseBackgroundForced(true);
        }
        
        else
        {
            finish();
        }
        return super.onOptionsItemSelected(item);
    }
}