calculator.java

带液晶显示的计算器

                        break;
                    case 1:
                        answerd -= Double.parseDouble(textResult);
                        break;
                    case 2:
                        answerd *= Double.parseDouble(textResult);
                        break;
                    case 3:
                        if (Double.parseDouble(textResult) == 0)
                        {
                            textResult="E";
                            clickable = false;
                        }
                        else
                        answerd /= Double.parseDouble(textResult);
                        break;
                    default:
                        answerd = Double.parseDouble(textResult);
                    }
                    textResult = "";
                    prekey = key = 2;
                }
                //'/'操作
                if (temp == buttonDiv)
                {
                    switch (prekey)
                    {
                    case 0:
                        answerd += Double.parseDouble(textResult);
                        break;
                    case 1:
                        answerd -= Double.parseDouble(textResult);
                        break;
                    case 2:
                        answerd *= Double.parseDouble(textResult);
                        break;
                    case 3:
                        if (Double.parseDouble(textResult) == 0)
                        {
                            textResult="E";
                            clickable = false;
                        }
                        else
                        answerd /= Double.parseDouble(textResult);
                        break;
                    default:
                        answerd = Double.parseDouble(textResult);
                    }
                    textResult = "";
                    prekey = key = 3;
                }
            }
            //'='操作
            if (temp == buttonEqual && clickable == true)
            {
                //如果连续按'=',则进行连续运算
                clear=true;
                if (prekey == 5)
                {
                    if (key == 0)
                    {
                        answerd += vard;
                        textResult = df.format(answerd);
                    }
                    if (key == 1)
                    {
                        answerd -= vard;
                        textResult = df.format(answerd);
                    }
                    if (key == 2)
                    {
                        answerd *= vard;
                        textResult = df.format(answerd);
                    }
                    if (key == 3)
                    {
                        if (Double.parseDouble(textResult) == 0)
                        {
                            textResult="E";
                            clickable = false;
                        }
                        else
                        {
                            answerd /= vard;
                            textResult = df.format(answerd);
                        }
                    }
                }
                else
                {
                    vard = Double.parseDouble(textResult);
                    if (key == 0)
                    {
                        prekey = -1;
                        answerd += Double.parseDouble(textResult);
                        textResult = df.format(answerd);
                    }
                    if (key == 1)
                    {
                        prekey = -1;
                        answerd -= Double.parseDouble(textResult);
                        textResult = df.format(answerd);
                    }
                    if (key == 2)
                    {
                        prekey = -1;
                        answerd *= Double.parseDouble(textResult);
                        textResult = df.format(answerd);
                    }
                    if (key == 3)
                    {
                        prekey = -1;
                        if (Double.parseDouble(textResult) == 0)
                        {
                            textResult="E";
                            clickable = false;
                        }
                        else
                        {
                            answerd /= Double.parseDouble(textResult);
                            textResult = df.format(answerd);
                        }
                    }
                }
                prekey = 5;
            }
            //'%'操作，对第二个操作数除以100
            if (temp == buttonMod && clickable == true)
            {
                if (answerd == 0)
                {
                    String s = textResult;
                    textResult = s;
                }
                else
                {
                    boolean isDot = false;
                    for (int i = 0; i < textResult.length(); i++)
                    if ('.' == textResult.charAt(i))
                    {
                        isDot = true;
                        break;
                    }
                    //如果是double数，除100
                    if (isDot == true)
                    {
                        double dtemp = Double.parseDouble(textResult);
                        dtemp = dtemp / 100.0;
                        textResult = Double.toString(dtemp);
                    }
                    else
                    {
                        //如果是int数但能被100整除，则去掉末尾两个零
                        if (Integer.parseInt(textResult) % 100 == 0)
                        {
                            int itemp = Integer.parseInt(textResult);
                            itemp /= 100;
                            textResult = Integer.toString(itemp);
                        }
                        //如果是int数，但不能被100整除，则按double数处理
                        else
                        {
                            double dtemp = Double.parseDouble(textResult);
                            dtemp = dtemp / 100.0;
                            textResult = Double.toString(dtemp);
                        }
                    }
                }
            }
            //开根号运算
            if (temp == buttonSqrt && clickable == true)
            {
                String s = textResult;
                if (s.charAt(0) == '-')
                {
                    textResult="E";
                    clickable = false;
                }
                else
                textResult = Double.toString(java.lang.Math.sqrt(Double.parseDouble(textResult)));
            }
            //倒数运算
            if (temp == buttonDao && clickable == true)
            {
                if (textResult.charAt(0) == '0' && textResult.length() == 1)
                {
                    textResult = "E";
                    clickable = false;
                }
                else
                {
                    boolean isDec = true;
                    int     i,
                    j,
                    k;
                    String  s = Double.toString(1 / Double.parseDouble(textResult));
                    for (i = 0; i < s.length(); i++)
                    if (s.charAt(i) == '.')
                    break;
                    for (j = i + 1; j < s.length(); j++)
                    if (s.charAt(j) != '0')
                    {
                        isDec = false;
                        break;
                    }
                    if (isDec == true)
                    {
                        String stemp = "";
                        for (k = 0; k < i; k++)
                        stemp += s.charAt(k);
                        textResult = stemp;
                    }
                    else
                    textResult = s;
                }
            }
            //按下'+/-'按钮时处理
            if (temp == buttonAddAndSub && clickable == true)
            {
                boolean isNumber = true;
                String  s = textResult;
                for (int i = 0; i < s.length(); i++)
                if (!(s.charAt(i) >= '0' && s.charAt(i) <= '9' || s.charAt(i) == '.' || s.charAt(i) == '-'))
                {
                    isNumber = false;
                    break;
                }
                if (isNumber == true)
                {
                    if(!textResult.equals("0"))
                    {
                        //如果当前字符串首字母有'-'号,代表现在是个负数,再按下时,则将首符号去掉
                        if (s.charAt(0) == '-')
                        {
                            textResult = "";
                            for (int i = 1; i < s.length(); i++)
                            {
                                char a = s.charAt(i);
                                textResult = textResult + a;
                            }
                        }
                        //如果当前字符串第一个字符不是符号，则添加一个符号在首字母处
                        else
                        textResult = '-' + s;
                    }
                }
            }
            //计算器有关内存操作
            //'MC'的操作，将内存清0
            if (temp == buttonMC && clickable == true)
            {
                memoryd = memoryi = 0;
                textMemory.setText("");
            }
            //'MS'的操作，将当前文本框内容保存入内存，显示'M'
            if (temp == buttonMS && clickable == true)
            {
                boolean isDot = false;
                for (int i = 0; i < textResult.length(); i++)
                if ('.' == textResult.charAt(i))
                {
                    isDot = true;
                    break;
                }
                //如果是double,则存入memoryd(double存储器)
                if (isDot == true)
                {
                    memoryd = Double.parseDouble(textResult);
                    memoryi = 0; //保证存储器中存放最新的值
                }
                //如果是int,则存入memoryi(int存储器)
                else
                {
                    memoryi = Integer.parseInt(textResult);
                    memoryd = 0; //保证存储器中存放最新的值
                }
                if(memoryd!=0||memoryi!=0)textMemory.setText("   M");
                else textMemory.setText("");
                clear=true;
            }
            //'MR'的操作，将存储器中的信息输出
            if (temp == buttonMR && clickable == true)
            {
                if (memoryd != 0)
                textResult = Double.toString(memoryd);
                else if(memoryi != 0)
                textResult = Integer.toString(memoryi);
                else if(memoryd==0 && memoryi==0) 
                textResult="0";
                clear=true;
            }
            //'M+'的功能，将当前文本框里的数据和存储器中数据相加后，再存入存储器
            if (temp == buttonMAdd && clickable == true)
            {
                boolean isDot = false;
                for (int i = 0; i < textResult.length(); i++)
                if ('.' == textResult.charAt(i))
                {
                    isDot = true;
                    break;
                }
                if (memoryd == 0 && isDot == false)
                {
                    memoryi += Integer.parseInt(textResult);
                    memoryd = 0;
                }
                else
                {
                    memoryd = memoryd + memoryi + Double.parseDouble(textResult);
                    memoryi = 0;
                }
                if(memoryd!=0 || memoryi!=0)textMemory.setText("   M");
                else textMemory.setText("");
                clear=true;
            }
            //按下'Backspace'键，利用循环将当前字符串中的最后一个字母删除
            if (temp == buttonBk && clickable == true)
            {
                String s = textResult;
                textResult = "";
                for (int i = 0; i < s.length() - 1; i++)
                {
                    char a = s.charAt(i);
                    textResult = textResult + a;
                }
                if(textResult.equals(""))textResult="0";
            }