科学计算器程序Java代码

功能举例：源程序如下：importjava.awt.BorderLayout;importjava.awt.Color;importjava.awt.Dimension;importjava.awt.Font;importjava.awt.GridLayout;importjava.awt.event.ActionEvent;importjava.awt.event.ActionListener;importjava.text.DecimalFormat;importjavax.swing.BorderFactory;importjavax.swing.ButtonGroup;importjavax.swing.JButton;importjavax.swing.JCheckBoxMenuItem;importjavax.swing.JFrame;importjavax.swing.JMenu;importjavax.swing.JMenuBar;importjavax.swing.JMenuItem;importjavax.swing.JPanel;importjavax.swing.JRadioButtonMenuItem;importjavax.swing.JTextField;publicclassCalucatorextendsJFrame{ privateJTextFieldtf; privateJPanelpanel1,panel2,panel3,panel4; privateJMenuBarmyBar; privateJMenumenu1,menu2,menu3; privateJMenuItemeditItem1,editItem2,help1,help2,help3; privateJRadioButtonMenuItemseeItem1,seeItem2;//单选框 privateJCheckBoxMenuItemseeItem3;//复选框 privateButtonGroupbgb; privateStringback; privatebooleanIfResult=true,flag=false; privateStringoper="="; privatedoubleresult=0; privateNumnumActionListener; privateDecimalFormatdf; publicCalucator(){ super("科学计算器");//设置标题栏 df=newDecimalFormat("#.####");//保留四位小数 this.setLayout(newBorderLayout(10,5)); panel1=newJPanel(newGridLayout(1,3,10,10)); panel2=newJPanel(newGridLayout(5,6,5,5));//5行6列 panel3=newJPanel(newGridLayout(5,1,5,5)); panel4=newJPanel(newBorderLayout(5,5)); /** *菜单栏 */ myBar=newJMenuBar(); menu1=newJMenu("编辑(E)"); menu2=newJMenu("查看(V)"); menu3=newJMenu("帮助(H)"); menu1.setFont(newFont("宋体",Font.PLAIN,12)); menu2.setFont(newFont("宋体",Font.PLAIN,12)); menu3.setFont(newFont("宋体",Font.PLAIN,12)); /** *编辑栏 */ editItem1=newJMenuItem("复制(C)Ctrl+C"); editItem2=newJMenuItem("粘贴(P)Ctrl+V"); editItem1.setFont(newFont("宋体",Font.PLAIN,12)); editItem2.setFont(newFont("宋体",Font.PLAIN,12)); addButton(panel2,"-/+",newClear(),Color.blue); addButton(panel2,".",newDot(),Color.blue); addButton(panel2,"+",newSigns(),Color.red); addButton(panel2,"tan",newSigns(),Color.magenta); addButton(panel2,"%",newSigns(),Color.magenta); addButton(panel2,"π",numActionListener,Color.orange); addButton(panel2,"e",numActionListener,Color.orange); addButton(panel2,"′″",newSigns(),Color.orange); addButton(panel2,"=",newSigns(),Color.red); JButtonbtns=newJButton("计算器"); btns.setBorder(BorderFactory.createLoweredBevelBorder()); btns.setEnabled(false);//按钮不可操作 btns.setPreferredSize(newDimension(20,20)); panel3.add(btns);//加入按钮 addButton(panel3,"MC",null,Color.red); addButton(panel3,"MR",null,Color.red); addButton(panel3,"MS",null,Color.red); addButton(panel3,"M+",null,Color.red); panel4.add(panel1,BorderLayout.NORTH); panel4.add(panel2,BorderLayout.CENTER); this.add(tf,BorderLayout.NORTH); this.add(panel3,BorderLayout.WEST); this.add(panel4); pack(); this.setResizable(false);//窗口不可改变大小 this.setLocation(300,200); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } /** *统一设置按钮的的使用方式 *@parampanel *@paramname *@paramaction *@paramcolor */ privatevoidaddButton(JPanelpanel,Stringname,ActionListeneraction,Colorcolor){ JButtonbt=newJButton(name); panel.add(bt);//在面板上增加按钮 bt.setForeground(color);//设置前景（字体）颜色 bt.addActionListener(action);//增加监听事件 } /** *计算器的基础操作（+-×÷） *@paramx */ privatevoidgetResult(doublex){ if(oper=="+"){result+=x;} elseif(oper=="-"){result-=x;} elseif(oper=="×"){result*=x;} elseif(oper=="÷"){result/=x;} elseif(oper=="="){result=x;} tf.setText(df.format(result)); } /** *运算符号的事件监听 */ classSignsimplementsActionListener{ publicvoidactionPerformed(ActionEvente){ /* *用ActionEvent对象的getActionCommand()方法 *取得与引发事件对象相关的字符串 */ Stringstr=e.getActionCommand(); /*sqrt求平方根*/ if(str.equals("sqrt")){ doublei=Double.parseDouble(tf.getText()); if(i>=0){ /* *String.valueOf()转换为字符串 *df.format()按要求保留四位小数 *Math.sqrt()求算数平方根 */ tf.setText(String.valueOf(df.format(Math.sqrt(i)))); } else{ tf.setText("负数不能开平方根"); } } /*log求常用对数*/ elseif(str.equals("log")){ doublei=Double.parseDouble(tf.getText()); if(i>0){ tf.setText(String.valueOf(df.format(Math.log(i)))); }else{ tf.setText("负数不能求对数"); } } /*%求百分比*/ elseif(str.equals("%")){ tf.setText(df.format(Double.parseDouble(tf.getText())/100)); } /*1/x求倒数*/ elseif(str.equals("1/x")){ if(Double.parseDouble(tf.getText())==0){ tf.setText("除数不能为零"); }else{ tf.setText(df.format(1/Double.parseDouble(tf.getText()))); } } /*sin求正弦函数*/ elseif(str.equals("sin")){ doublei=Double.parseDouble(tf.getText()); tf.setText(String.valueOf(df.format(Math.sin(i)))); } /*cos求余弦函数*/ elseif(str.equals("cos")){ doublei=Double.parseDouble(tf.getText()); tf.setText(String.valueOf(df.format(Math.cos(i)))); } /*tan求正切函数*/ elseif(str.equals("tan")){ doublei=Double.parseDouble(tf.getText()); tf.setText(String.valueOf(df.format(Math.tan(i)))); } /*n!求阶乘*/ elseif(str.equals("n!")){ doublei=Double.parseDouble(tf.getText()); if((i%2==0)||(i%2==1))//判断为整数放进行阶乘操作 { intj=(int)i;//强制类型转换 intresult=1; for(intk=1;k<=j;k++) result*=k; tf.setText(String.valueOf(result)); } else { tf.setText("无法进行阶乘"); } } /*x^2求平方*/ elseif(str.equals("x^2")){ doublei=Double.parseDouble(tf.getText()); tf.setText(String.valueOf(df.format(i*i))); } /*x^3求立方*/ elseif(str.equals("x^3")){ doublei=Double.parseDouble(tf.getText()); tf.setText(String.valueOf(df.format(i*i*i))); } /*′″角度转换*/ /** *将角度值转换成弧度值，方便三角函数的计算 */ elseif(str.equals("′″")){ doublei=Double.parseDouble(tf.getText()); tf.setText(String.valueOf(i/180*Math.PI)); } else{ if(flag){ IfResult=false; } if(IfResult){ oper=str; }else{ getResult(Double.parseDouble(tf.getText())); oper=str; IfResult=true; } } } } /** *清除按钮的事件监听 */ classClearimplementsActionListener{ publicvoidactionPerformed(ActionEvente){ /* *用ActionEvent对象的getActionCommand()方法 *取得与引发事件对象相关的字符串 */ Stringstr=e.getActionCommand(); if(str=="C"){ tf.setText("0"); IfResult=true; result=0; }elseif(str=="-/+"){ doublei=0-Double.parseDouble(tf.getText().trim()); tf.setText(df.format(i)); }elseif(str=="Backspace"){ if(Double.parseDouble(tf.getText())>0){ if(tf.getText().length()>1){ tf.setText(tf.getText().substring(0,tf.getText().length()-1)); //使用退格删除最后一位字符 }else{ tf.setText("0"); IfResult=true; } }else{ if(tf.getText().length()>2){ tf.setText(tf.getText().substring(0,tf.getText().length()-1)); }else{ tf.setText("0"); IfResult=true; } } }elseif(str=="CE"){ tf.setText("0"); IfResult=true; } } } /** *数字输