calculator.java

java版计算器

                        break;
                    case 3:
                        if (Double.parseDouble(textAnswer.getText()) == 0) {
                            textAnswer.setText("除数不能为零");
                            clickable = false;
                        } else
                            answerd /= Double.parseDouble(textAnswer.getText());
                        break;
                    default:
                        answerd = Double.parseDouble(textAnswer.getText());
                    }
                    textAnswer.setText("");
                    prekey = key = 2;
                }
                // '/'操作
                if (temp == buttonDiv) {
                    switch (prekey) {
                    case 0:
                        answerd += Double.parseDouble(textAnswer.getText());
                        break;
                    case 1:
                        answerd -= Double.parseDouble(textAnswer.getText());
                        break;
                    case 2:
                        answerd *= Double.parseDouble(textAnswer.getText());
                        break;
                    case 3:
                        if (Double.parseDouble(textAnswer.getText()) == 0) {
                            textAnswer.setText("除数不能为零");
                            clickable = false;
                        } else
                            answerd /= Double.parseDouble(textAnswer.getText());
                        break;
                    default:
                        answerd = Double.parseDouble(textAnswer.getText());
                    }
                    textAnswer.setText("");
                    prekey = key = 3;
                }
            }
            // '='操作
            if (temp == buttonEqual && clickable == true) {
                // 如果连续按'=',则进行连续运算
                if (prekey == 5) {
                    if (key == 0) {
                        answerd += vard;
                        textAnswer.setText(df.format(answerd));
                    }
                    if (key == 1) {
                        answerd -= vard;
                        textAnswer.setText(df.format(answerd));
                    }
                    if (key == 2) {
                        answerd *= vard;
                        textAnswer.setText(df.format(answerd));
                    }
                    if (key == 3) {
                        if (Double.parseDouble(textAnswer.getText()) == 0) {
                            textAnswer.setText("除数不能为零");
                            clickable = false;
                        } else {
                            answerd /= vard;
                            textAnswer.setText(df.format(answerd));
                        }
                    }
                } else {
                    vard = Double.parseDouble(textAnswer.getText());
                    if (key == 0) {
                        prekey = -1;
                        answerd += Double.parseDouble(textAnswer.getText());
                        textAnswer.setText(df.format(answerd));
                    }
                    if (key == 1) {
                        prekey = -1;
                        answerd -= Double.parseDouble(textAnswer.getText());
                        textAnswer.setText(df.format(answerd));
                    }
                    if (key == 2) {
                        prekey = -1;
                        answerd *= Double.parseDouble(textAnswer.getText());
                        textAnswer.setText(df.format(answerd));
                    }
                    if (key == 3) {
                        prekey = -1;
                        if (Double.parseDouble(textAnswer.getText()) == 0) {
                            textAnswer.setText("除数不能为零");
                            clickable = false;
                        } else {
                            answerd /= Double.parseDouble(textAnswer.getText());
                            textAnswer.setText(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 = textAnswer.getText();
                    textAnswer.setText(s);
                } else {
                    boolean isDot = false;
                    for (int i = 0; i < textAnswer.getText().length(); i++)
                        if ('.' == textAnswer.getText().charAt(i)) {
                            isDot = true;
                            break;
                        }
                    // 如果是double数，除100
                    if (isDot == true) {
                        double dtemp = Double.parseDouble(textAnswer.getText());
                        dtemp = dtemp / 100.0;
                        textAnswer.setText(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(textAnswer.getText()) % 100 == 0) {
                            int itemp = Integer.parseInt(textAnswer.getText());
                            itemp /= 100;
                            textAnswer.setText(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(textAnswer.getText());
                            dtemp = dtemp / 100.0;
                            textAnswer.setText(Double.toString(dtemp));
                        }
                    }
                }
            }
            // 开根号运算
            if (temp == buttonSqrt && clickable == true) {
                String s = textAnswer.getText();
                if (s.charAt(0) == '-') {
                    textAnswer.setText("负数不能开根号");
                    clickable = false;
                } else
                    textAnswer.setText(Double.toString(java.lang.Math.sqrt(Double.parseDouble(textAnswer.getText()))));
            }
            // 倒数运算
            if (temp == buttonDao && clickable == true) {
                if (textAnswer.getText().charAt(0) == '0' && textAnswer.getText().length() == 1) {
                    textAnswer.setText("零不能求倒数");
                    clickable = false;
                } else {
                    boolean isDec = true;
                    int i, j, k;
                    String s = Double.toString(1 / Double.parseDouble(textAnswer.getText()));
                    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);
                        textAnswer.setText(stemp);
                    } else
                        textAnswer.setText(s);
                }
            }
            // 按下'+/-'按钮时处理
            if (temp == buttonAddAndSub && clickable == true) {
                boolean isNumber = true;
                String s = textAnswer.getText();
                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) {
                    // 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) == '-') {
                        textAnswer.setText("");
                        for (int i = 1; i < s.length(); i++) {
                            char a = s.charAt(i);
                            textAnswer.setText(textAnswer.getText() + 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
                        textAnswer.setText('-' + 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;
                textMemory.setText(" M");
                for (int i = 0; i < textAnswer.getText().length(); i++)
                    if ('.' == textAnswer.getText().charAt(i)) {
                        isDot = true;
                        break;
                    }
                // 如果是double,则存入memoryd(double存储器)
                if (isDot == true) {
                    memoryd = Double.parseDouble(textAnswer.getText());
                    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(textAnswer.getText());
                    memoryd = 0; // 保证存储器中存放最新的值
                }
            }
            // 'MR'的操作，将存储器中的信息输出
            if (temp == buttonMR && clickable == true) {
                if (memoryd != 0)
                    textAnswer.setText(Double.toString(memoryd));
                if (memoryi != 0)
                    textAnswer.setText(Integer.toString(memoryi));
            }
            // '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 < textAnswer.getText().length(); i++)
                    if ('.' == textAnswer.getText().charAt(i)) {
                        isDot = true;
                        break;
                    }
                if (memoryi != 0) { // 存储中是一个int型数
                    if (isDot == false) // 被加数是一个int型数
                        memoryi += Integer.parseInt(textAnswer.getText());
                    else { //被加数是一个double型数，则将int存储器中数传入double存储器与当前数相加，int存储器清零
                        memoryd = memoryi + Double.parseDouble(textAnswer.getText());
                        memoryi = 0;
                    }
                } else
                    memoryd += Double.parseDouble(textAnswer.getText());
            }
            // 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 = textAnswer.getText();
                textAnswer.setText("");
                for (int i = 0; i < s.length() - 1; i++) {
                    char a = s.charAt(i);
                    textAnswer.setText(textAnswer.getText() + a);
                }
            }
            // 按下'CE'按钮，将当前文本框内数据清除
            if (temp == buttonCe) {
                textAnswer.setText("");
                clickable = true;
            }
            // 按下'C'按钮，文本框内数据清除，同时var,answer清0
            if (temp == buttonC) {
                vard = answerd = 0;
                textAnswer.setText("");
                clickable = true;
            }
            // 按下'复制'菜单栏
            if (temp == copyItem) {
                copy = textAnswer.getText();
            }
            // 按下'粘贴'菜单栏
            if (temp == pasteItem) {
                textAnswer.setText(copy);
            }
            if (temp == sItem) {
                JOptionPane.showMessageDialog(panel, "当前是标准型计算器，科学型计算器有待更新。");
            }
            // 按下'帮助主题'菜单栏
            if (temp == topHelp) {
                JOptionPane.showMessageDialog(panel, scrollHelp);
            }
            // 按下'数字分组'菜单栏
            if (temp == numberGroup) {
                if (numberGroup.getText().compareTo(" 数字分组(I)") == 0)
                    numberGroup.setText("√数字分组(I)");
                else
                    numberGroup.setText(" 数字分组(I)");
            }
            // 按下'关于'菜单栏
            if (temp == aboutCal) {
                JOptionPane.showMessageDialog(panel, "计算器1.00版开发者：楼竞");
            }
        }
        // 输入中如果有操作非法，比如按下两次'+'，捕获异常
        catch (Exception e) {
            textAnswer.setText("操作非法");
            clickable = false;
        }
    }
    
  //主函数
    public static void main(String args[]) {
    new Calculator();
    }

}