gui.java

大一JAVA实习的题目

/**
 * Write a description of class GUI here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class GUI extends JFrame implements ActionListener
{
    private JTextArea myTextField=new JTextArea(1,25);
    
    private JButton Button[]=new JButton[19];
    
    private String s="";
    private int calcu;
    
    private double a=0,b=0;

    public GUI()
    {
        setTitle("计算器");
        myTextField.setLayout(new BorderLayout());
        
        add("North",myTextField);
        
        setLayout(new GridLayout(5,4));
        
        for(int i=0;i<10;i++)
            Button[i]=new JButton(""+i);
        Button[10]=new JButton("+");
        Button[11]=new JButton("-");
        Button[12]=new JButton("*");
        Button[13]=new JButton("/");
        Button[14]=new JButton("=");
        Button[15]=new JButton(".");
        Button[16]=new JButton("平方");
        Button[17]=new JButton("平方根");
        Button[18]=new JButton("AC");
        
        for(int i=0;i<19;i++)
            add(Button[i]);
        for(int i=0;i<19;i++)
            Button[i].addActionListener(this);
        
        
        setSize(300,300);
        
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e)
    {
        //calculate mycalculate=new calculate();
        if(e.getSource()==Button[0])
        {
            myTextField.append("0");
            s+="0";
        }
        
        if(e.getSource()==Button[1])
        {
            myTextField.append("1");
            s+="1";
        }
        
        if(e.getSource()==Button[2])
        {
            myTextField.append("2");
            s+="2";
        }
        
        if(e.getSource()==Button[3])
        {
            myTextField.append("3");
            s+="3";
        }
        
        if(e.getSource()==Button[4])
        {
            myTextField.append("4");
            s+="4";
        }
        
        if(e.getSource()==Button[5])
        {
            myTextField.append("5");
            s+="5";
        }
        
        if(e.getSource()==Button[6])
        {
            myTextField.append("6");
            s+="6";
        }
        
        if(e.getSource()==Button[7])
        {
            myTextField.append("7");
            s+="7";
        }
        
        if(e.getSource()==Button[8])
        {
            myTextField.append("8");
            s+="8";
        }
        
        if(e.getSource()==Button[9])
        {
            myTextField.append("9");
            s+="9";
        }
        
        if(e.getSource()==Button[15])
        {
            myTextField.append(".");
            s+=".";
        }
        
        if(e.getSource()==Button[10])
        {
            a=Double.parseDouble(s);
            myTextField.setText("+");
            calcu=1;
            s="";
        }
        
        if(e.getSource()==Button[11])
        {
            a=Double.parseDouble(s);
            myTextField.setText("-");
            calcu=2;
            s="";
        }
        
        if(e.getSource()==Button[12])
        {
            a=Double.parseDouble(s);
            myTextField.setText("*");
            calcu=3;
            s="";
        }
        
        if(e.getSource()==Button[13])
        {
            a=Double.parseDouble(s);
            myTextField.setText("/");
            calcu=4;
            s="";
        }
        
        if(e.getSource()==Button[14])
        {
            double r=0;
            b=Double.parseDouble(s);
            switch(calcu)
            {
                case 1 :r=a+b;break;
                case 2 :r=a-b;break;
                case 3 :r=a*b;break;
                case 4 :r=a/b;break;
            }
            myTextField.setText(""+r);
            a=0;b=0;s="";
        }
        
        if(e.getSource()==Button[16])
        {
            a=Double.parseDouble(s);
            myTextField.setText(""+(a*a));
        }
        
        if(e.getSource()==Button[17])
        {
            a=Double.parseDouble(s);
            myTextField.setText(""+Math.sqrt(a));
        }
        
        if(e.getSource()==Button[18])
        {
            a=0;b=0;s="";
            myTextField.setText("");
        }
    }
}