【java图形计算器】 java awt swing组件应用

package package1;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import java.util.LinkedList;
import java.text.NumberFormat;

public class Computer extends Frame implements ActionListener{

    NumberButton numberButton[];
    OperationButton operationButton[];
    Button 小数点按钮 , 正负号按钮 , 退格按钮 , 求倒数按钮 , 等号按钮 , 清零按钮 ;
    Panel panel;
    JTextField resultShow;
    String 运算符号[]={"+","-","*","/"};
    LinkedList linklist;
    boolean 是否按下等号=false;

    public Computer(){
        super("科学计算器");
        linklist=new LinkedList();
        numberButton=new NumberButton[10];
        for(int i=0;i<=9;i++){
            numberButton[i]=new NumberButton(i);
            numberButton[i].addActionListener(this);
        }

        operationButton=new OperationButton[4];
        for(int i=0;i<=3;i++){
            operationButton[i]=new OperationButton(运算符号[i]);
            operationButton[i].addActionListener(this);
        }

        退格按钮=new Button("back");
        清零按钮=new Button("C");
        等号按钮=new Button("=");
        小数点按钮=new Button(".");
        正负号按钮=new Button("+/-");
        求倒数按钮=new Button("1/x");

        退格按钮.setForeground(Color.red);
        清零按钮.setForeground(Color.red);
        等号按钮.setForeground(Color.red);
        小数点按钮.setForeground(Color.blue);
        正负号按钮.setForeground(Color.blue);
        求倒数按钮.setForeground(Color.blue);

        退格按钮.addActionListener(this);
        清零按钮.addActionListener(this);
        等号按钮.addActionListener(this);
        小数点按钮.addActionListener(this);
        正负号按钮.addActionListener(this);
        求倒数按钮.addActionListener(this);

        resultShow=new JTextField(10);
        resultShow.setHorizontalAlignment(JTextField.RIGHT);
        resultShow.setForeground(Color.blue);
        resultShow.setFont(new Font("TimeRoman",Font.PLAIN,14));
        resultShow.setBorder(new SoftBevelBorder(BevelBorder.LOWERED));
        resultShow.setBackground(Color.white);
        resultShow.setEditable(false);

        panel=new Panel();
        panel.setLayout(new GridLayout(4,5));
        panel.add(numberButton[1]);
        panel.add(numberButton[2]);
        panel.add(numberButton[3]);
        panel.add(operationButton[0]);
        panel.add(清零按钮);

        panel.add(numberButton[4]);
        panel.add(numberButton[5]);
        panel.add(numberButton[6]);
        panel.add(operationButton[1]);
        panel.add(退格按钮);

        panel.add(numberButton[7]);
        panel.add(numberButton[8]);
        panel.add(numberButton[9]);
        panel.add(operationButton[2]);
        panel.add(求倒数按钮);

        panel.add(numberButton[0]);
        panel.add(正负号按钮);
        panel.add(小数点按钮);
        panel.add(operationButton[3]);
        panel.add(等号按钮);

        add(panel,BorderLayout.CENTER);
        add(resultShow,BorderLayout.NORTH);
        setBounds(100,50,300,240);
        setVisible(true);

        addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e){
                System.exit(0);
            }
        });
    }

        public void actionPerformed(ActionEvent e){
            if(e.getSource() instanceof NumberButton){
                NumberButton b=(NumberButton)e.getSource();
                if(linklist.size()==0){
                    int number=b.getNumber();
                    linklist.add(""+number);
                    resultShow.setText(""+number);
                    是否按下等号=false;
                }
                else if(linklist.size()==1 && 是否按下等号==false){
                    int number=b.getNumber();
                    String num=(String)linklist.getFirst();
                    String s=num.concat(""+number);
//                     E  set(int index, E element)        将此列表中指定位置的元素替换为指定的元素。
                    linklist.set(0,s);
                    resultShow.setText(s);
                }
                else if(linklist.size()==1 && 是否按下等号==true){
                    int number=b.getNumber();
                    linklist.removeFirst();
                    linklist.add(""+number);
                    是否按下等号=false;
                    resultShow.setText(""+number);
                }
                else if(linklist.size()==2){
                    int  number=b.getNumber();
                    linklist.add(""+number);
                    resultShow.setText(""+number);
                }
                else if(linklist.size()==3){
                    int  number=b.getNumber();
                    String num=(String)linklist.getLast();
                    String s=num.concat(""+number);
                    linklist.set(2,s);
                    resultShow.setText(s);
                }
            }

            else if(e.getSource() instanceof OperationButton){
                OperationButton b=(OperationButton)e.getSource();
                if(linklist.size()==1){
                    String mark=b.getOperator();
                    linklist.add(mark);
                }
                else if(linklist.size()==2){
                    String mark=b.getOperator();
                    linklist.set(1,mark);
                }
                else if(linklist.size()==3){
                    String mark=b.getOperator();
                    String num1=(String)linklist.getFirst();
                    String num2=(String)linklist.getLast();
                    String 运算符号=(String)linklist.get(1);

                    double n1=Double.parseDouble(num1);
                    double n2=Double.parseDouble(num2);
                    double n=0;
                    if(运算符号.equals("+"))n=n1+n2;
                    else if(运算符号.equals("-"))n=n1-n2;
                    else if(运算符号.equals("*"))n=n1*n2;
                    else if(运算符号.equals("/"))n=n1/n2;
                    linklist.clear();
                    linklist.add(""+n);
                    linklist.add(mark);
                    resultShow.setText(""+n);
                }
            }

            else if(e.getSource()==等号按钮){
                是否按下等号=true;
                if(linklist.size()==1 || linklist.size()==2){
                    String num=(String)linklist.getFirst();
                    resultShow.setText(""+num);
                }
                else if(linklist.size()==3){
                    String num1=(String)linklist.getFirst();
                    String num2=(String)linklist.getLast();
                    String 运算符号=(String)linklist.get(1);

                    double n1=Double.parseDouble(num1);
                    double n2=Double.parseDouble(num2);
                    double n=0;
                    if(运算符号.equals("+"))n=n1+n2;
                    else if(运算符号.equals("-"))n=n1-n2;
                    else if(运算符号.equals("*"))n=n1*n2;
                    else if(运算符号.equals("/"))n=n1/n2;
                    linklist.clear();
                    linklist.add(""+n);
                    resultShow.setText(""+n);
                }
            }

            else if(e.getSource()==小数点按钮){
//                if(linklist.size()==0){
//                    是否按下等号=false;
//                }
                if(linklist.size()==1){
                    String dot=小数点按钮.getLabel();
                    String num=(String) linklist.getFirst();
                    String s=null;
                    if(num.indexOf(dot)==-1){
                        s=num.concat(dot);
                        linklist.set(0,s);
                    }
                    else s=num;
                    linklist.set(0,s);
                    resultShow.setText(s);
                }
                else if(linklist.size()==3){
                    String dot=小数点按钮.getLabel();
                    String num=(String) linklist.getLast();
                    String s=null;
                    if(num.indexOf(dot)==-1){
                        s=num.concat(dot);
                        linklist.set(2,s);
                    }
                    else s=num;
                    linklist.set(2,s);
                    resultShow.setText(s);
                }
            }

            else if(e.getSource()==退格按钮){
                if(linklist.size()==1){
                    String num=(String) linklist.getFirst();
                    if(num.length()>=1){
                        num=num.substring(0,num.length()-1);
                        linklist.set(0,num);
                        resultShow.setText(num);
                    }
                    else{
                        linklist.removeLast();
                        resultShow.setText("0");
                    }
                }

                if(linklist.size()==3){
                    String num=(String) linklist.getLast();
                    if(num.length()>=1){
                        num=num.substring(0,num.length()-1);
                        linklist.set(2,num);
                        resultShow.setText(num);
                    }
                    else{
                        linklist.removeLast();
                        resultShow.setText("0");
                    }
                }
            }

            else if(e.getSource()==正负号按钮){
                if(linklist.size()==1){
                    String num=(String) linklist.getFirst();
                    double d=Double.parseDouble(num);
                    d=-1*d;
                    String str=String.valueOf(d);
                    linklist.set(0,str);
                    resultShow.setText(str);
                }
                else if(linklist.size()==3){
                    String num=(String) linklist.getLast();
                    double d=Double.parseDouble(num);
                    d=-1*d;
                    String str=String.valueOf(d);
                    linklist.set(2,str);
                    resultShow.setText(str);
                }
            }

            else if(e.getSource()==求倒数按钮){
                if(linklist.size()==1 || linklist.size()==2){
                    String num=(String) linklist.getFirst();
                    double d=Double.parseDouble(num);
                    d=1.0/d;
                    String str=String.valueOf(d);
                    linklist.set(0,str);
                    resultShow.setText(str);
                }
                else if(linklist.size()==3){
                    String num=(String) linklist.getLast();
                    double d=Double.parseDouble(num);
                    d=1.0/d;
                    String str=String.valueOf(d);
                    linklist.set(2,str);
                    resultShow.setText(str);
                }
            }

            else if(e.getSource()==清零按钮){
                是否按下等号=false;
                resultShow.setText("0");
                linklist.clear();
            }

        }

    public static void main(String[] args)
    {
        new Computer();
    }
}

class NumberButton extends Button{
    int number;
    public NumberButton(int number){
        super(""+number);
        this.number=number;
        setForeground(Color.blue);
    }
    public int getNumber(){
        return number;
    }
}

class OperationButton extends Button{
    String operator;
    public OperationButton(String operator){
        super(operator);
        this.operator=operator;
        setForeground(Color.red);
    }
    public String getOperator(){
        return operator;
    }
}

运行结果：