Java swing 计算器

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import java.awt.*; import javax.swing.*; import java.awt.event.*; class calculation extends JFrame   {public calculation()     /*构造方法*/    {super("计数器");     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     initTextPanel();    /*文本框*/     initControlPanel(); /*控制键*/     initKeyPanel();     /*数字和运算符*/     Container pane = getContentPane();     pane.setLayout(new BorderLayout());     pane.add(TextPanel,BorderLayout.NORTH);     pane.add(ControlPanel,BorderLayout.CENTER);         pane.add(KeyPanel,BorderLayout.SOUTH);     pack();         try     {UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");           }     catch(Exception ex)     {;}        /*设置Windons观感*/     SwingUtilities.updateComponentTreeUI(this);     setResizable(false);     setVisible(true);      } private void initTextPanel()  /*设置文本框*/  {  TextPanel=new JPanel();     TextPanel.setLayout(new FlowLayout());          Resultarea =new JTextField("0",25);           Resultarea.setEditable(false);  /*设置不可编辑*/      Color color=Color.white;      Resultarea.setBackground(color);   /*颜色*/      Resultarea.setHorizontalAlignment(JTextField.RIGHT);    /*设置显示位置*/      TextPanel.add(Resultarea);    } private void initControlPanel() /*设置控制键*/  {ControlPanel=new JPanel();   ControlPanel.setLayout(new GridLayout(1,3,4,4));     JButton b1=new JButton("Backspace");    /*Backspace键*/   b1.setFont(font1);   b1.addActionListener(new ActionListener()         {public void actionPerformed(ActionEvent e)         {String s1=Resultarea.getText();          int l=s1.length();          Resultarea.setText(s1.substring(0 ,l-1));         }      });  ControlPanel.add(b1);   JButton b2=new JButton("CE");   /*CE键*/   b2.setFont(font1);   b2.addActionListener(new ActionListener()     {public void actionPerformed(ActionEvent e)         {Resultarea.setText("0");         isNew=true;        }      });       ControlPanel.add(b2);  JButton b3=new JButton("C");  /*C键*/   b3.setFont(font1);   b3.addActionListener(new ActionListener()      {public void actionPerformed(ActionEvent e)          {Resultarea.setText("0");          pnum="";          operation="";          isNew=true;         }      });       ControlPanel.add(b3);     } private void initKeyPanel()   /*设置数字键和运算符键*/  {String key[] = {"7","8","9","/","sqrt","4","5","6","*","%","1","2","3","-","1/x","0","+/-",".","+","="};     KeyPanel = new JPanel();     KeyPanel.setLayout(new GridLayout(4,5,4,4));     for(int i=0;i<20;i++)       {String label = key[i];        JButton b = new JButton(label);        b.setActionCommand(key[i]);        b.setFont(font2);        KeyPanel.add(b);        b.addActionListener(new ActionListener()  /*无名监听器*/         {public void actionPerformed(ActionEvent e)            {Key_actionPerformed(e);            }         });       }   }  public void Key_actionPerformed(ActionEvent e) /*数字键和运算符键无名监听器*/        {String s=(e.getActionCommand());         String st=Resultarea.getText();               if(s.equals("0"))          /*输入数为0*/              {if(st.equals("0"))                 return;               else                  {if(!isNew)                                    Resultarea.setText(st+"0");                   else                    Resultarea.setText("0");                               }                isNew=false;               return;             }          if(s.equals("+/-"))  /*输入数为+/-*/              {double k=Double.parseDouble(st);                          {if(k!=0)                    display(-k);                }               return;                 }         if(s.equals("1")||s.equals("2")||s.equals("3")||s.equals("4")||s.equals("5")||s.equals("6")||s.equals("7")||s.equals("8")||s.equals("9")) /*输入1-9*/                  {if(!isNew)                     Resultarea.setText(st+s);                   else                     { Resultarea.setText(s);                          isNew=false;                         }                    return;                    }         if(s.equals("."))  /*输入小数点*/             {if(Resultarea.getText().indexOf(".")==-1)  /*不存在小数点*/                {if(isNew)                                      {Resultarea.setText("0.");                                        isNew=false;                    }                 else                     Resultarea.setText(st+".");                }              return;             }         isNew=true;          /*按下运算符，输入新的数*/                           if(s.equals("="))              {compute(s);                   operation="";                                    }          else              {if(s.equals("+")||s.equals("-")||s.equals("*")||s.equals("/")) /*二目运算符号*/                 {if(operation.equals(""))                     {pnum=Resultarea.getText();                                              operation=s;                                                }                                             else                     compute(s);                                       }                                         else   /*一目运算*/                 {Count count1=new Count(Double.parseDouble(st));                  if(s.equals("sqrt"))                     {                       display(count1.sqrt());                     }                   else                     {if(s.equals("1/x"))                             {if(st.equals("0"))                           {Resultarea.setText("除数不能为0.");                            operation="";                            pnum="";                           }                         else                              display(count1.reciprocal());     /*求倒数*/                        }                      else                        display(Double.parseDouble(st)/100);  /*输入%，使当前显示的值除于100*/                     }                  }               }           }  private void compute(String s)   {if(s.equals("="))      {if(operation.equals(""))              return;                       }                 double data1=Double.parseDouble(pnum);    double  data2=Double.parseDouble(Resultarea.getText());             Count count2=new Count(data1,data2);    /*加减乘除计算*/    if(operation.equals("+"))       display((count2.plus()));                           else            {if(operation.equals("-"))            display((count2.minus()));                  else           {if(operation.equals("*"))              display((count2.multiply()));            else              if(operation.equals("/"))                    {if(data2==0)                      {Resultarea.setText("除数不能为0");                       operation="";                    pnum="";                      return;                                         }                    else                      display((count2.divide()));                     }                 }       }                operation="";  /*符号为当前符*/    pnum=Resultarea.getText();/*运算数为当前文本数*/                }     public void display(double result)   /*显示输出方法*/    {int a=(int)result;     if(a==result)        Resultarea.setText(String.valueOf(a));     else        Resultarea.setText(String.valueOf(result));     if(Resultarea.getText().equals("NaN"))       Resultarea.setText("输入函数无效");       }        private JPanel TextPanel;   /*文本框棉板*/   private JTextField Resultarea;  /*文本框*/   private JPanel ControlPanel;  /*控制键键面板*/   private JPanel KeyPanel;      /*数字键和运算符键面板*/   private Font font1=new Font("Dialog",0, 10);  /*控制键字体*/   private Font font2 = new Font("Dialog",0,10); /*数字键和符号键字体*/    private String  pnum="";   /*前操作数*/   private boolean isNew=true; /*控制是否是新数*/     private String operation="";    /*运算符*/  }  class tester  /*测试类*/ {   public static void main(String[] args)   {     new calculation();   } }
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