huyuena.java

自己用JAVA做的一个小计算器的源代码

/*
 * @(#)Huyuena.java 1.0 04/11/13
 *
 * You can modify the template of this file in the
 * directory ..\JCreator\Templates\Template_1\Project_Name.java
 *
 * You can also create your own project template by making a new
 * folder in the directory ..\JCreator\Template\. Use the other
 * templates as examples.
 *
 */
package myprojects.huyuena;

import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;

public class Huyuena implements ActionListener 
{
	public static void main(String args[])
	{
		new Huyuena();
	}  	
	Frame fr;
	TextField textAnswer;
	Panel panel,panel1,panel2;
	Button button[],A,B,C,D,E,F,G,H,I,J;
	DecimalFormat df; 
	String flg;
	boolean ca; 
	double vard,answerd; 
	short key=-1,prekey=-1; 
	public Huyuena()
	{
		ca=true;
		answerd=0;
		fr=new Frame("简单的计算器");
		df=new DecimalFormat("0.########"); 
		textAnswer=new TextField(10);
		panel=new Panel();
		fr.add(panel);
		panel1=new Panel();       
		panel2=new Panel();
		panel.setLayout(new BorderLayout());
        panel.add(textAnswer,BorderLayout.CENTER);
        panel.add(panel1, BorderLayout.SOUTH);
        panel1.setLayout(new BorderLayout());
        panel1.add(panel2, BorderLayout.CENTER);        
        button=new Button[10];
        for(int i=0; i<button.length;i++)
        {
        	button[i]=new Button(Integer.toString(i));
        }
        A=new Button("+");
        A.setForeground(new Color(0,0,255));
        B=new Button("-");
        B.setForeground(new Color(0,0,255));
        C=new Button("*");
        C.setForeground(new Color(0,0,255));
        D=new Button("/");
        D.setForeground(new Color(0,0,255));
        E=new Button("%");    
        E.setForeground(new Color(0,0,255));
        F=new Button("Clear");
        F.setForeground(new Color(255,0,0));
        G=new Button("sqrt");
        G.setForeground(new Color(0,0,255));
        H=new Button("1/x");
        H.setForeground(new Color(0,0,255));
        I=new Button("=");
        I.setForeground(new Color(255,0,0));
        J=new Button(".");

        panel2.setLayout(new GridLayout(4, 5));   
        button[7].addActionListener(this);   
        button[8].addActionListener(this);    
        button[9].addActionListener(this);
        A.addActionListener(this);
        F.addActionListener(this);       
        button[4].addActionListener(this);    
        button[5].addActionListener(this);   
        button[6].addActionListener(this);
        B.addActionListener(this);   
        G.addActionListener(this);                  
        button[1].addActionListener(this);    
        button[2].addActionListener(this);    
        button[3].addActionListener(this);   
        C.addActionListener(this);
        H.addActionListener(this);   
        button[0].addActionListener(this);           
        J.addActionListener(this);
        E.addActionListener(this);      
        D.addActionListener(this);   
        I.addActionListener(this);
        
        panel2.add(button[7]);
        panel2.add(button[8]);
        panel2.add(button[9]);
        panel2.add(A);    
        panel2.add(F);
        panel2.add(button[4]);
        panel2.add(button[5]);
        panel2.add(button[6]);
        panel2.add(B);
        panel2.add(G);       
        panel2.add(button[1]);
        panel2.add(button[2]);
        panel2.add(button[3]);
        panel2.add(C);    
        panel2.add(H);
        panel2.add(button[0]);   
        panel2.add(J);
        panel2.add(E);
        panel2.add(D);
        panel2.add(I);
        fr.pack();
        fr.show();
     }
public void actionPerformed(ActionEvent event) 
{
  	boolean sign=false; 
  	Object temp=event.getSource();
    try {                
         for (int i=0;i<=9;i++)
         if (temp==button[i]&&ca==true)
         textAnswer.setText(textAnswer.getText()+Integer.toString(i));
         if (temp==J&&ca==true)
         {
         	boolean isJ=false;
         	if (textAnswer.getText().length()==0)
         	isJ=true;
         	for (int i=0; i<textAnswer.getText().length();i++)
         	if ('.'==textAnswer.getText().charAt(i)) 
         	{
         		isJ=true;
                break;
            }
            if (isJ==false)
            textAnswer.setText(textAnswer.getText()+".");
         }
if ((temp==A||temp==B||temp==C||temp==D) && ca==true) 
{
    if(temp==A)
    {         
        answerd=Double.parseDouble(textAnswer.getText());
        textAnswer.setText("");
        prekey=key=0;
    }      
    if (temp==B) 
    {
        answerd=Double.parseDouble(textAnswer.getText());
        textAnswer.setText("");
        prekey=key=1;
    }      
    if (temp==C) 
    {
        answerd=Double.parseDouble(textAnswer.getText());
        textAnswer.setText("");
        prekey=key=2;
    }        
    if (temp==D) 
    {
        answerd=Double.parseDouble(textAnswer.getText());
        textAnswer.setText("");
        prekey = key = 3;
    }
}
if (temp==I&&ca==true) 
{
    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) 
        {           
            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");
                   ca=false;
                }
                else 
                {
                	answerd/=Double.parseDouble(textAnswer.getText());
                    textAnswer.setText(df.format(answerd));
                }
            }
        }
        prekey=5;
}
     if (temp==E && ca==true) 
     {
        double dtemp=Double.parseDouble(textAnswer.getText());
        dtemp=dtemp/100.0;
        textAnswer.setText(Double.toString(dtemp));
  
     }
     if (temp==G&&ca==true) 
     {
      	String s=textAnswer.getText();
        if (s.charAt(0)=='-') 
        {
          textAnswer.setText("负数不能开根号");
          ca=false;
        }
        else
          textAnswer.setText(Double.toString(java.lang.Math.sqrt(Double.
          parseDouble(textAnswer.getText()))));
     }
     if (temp==H&&ca==true) 
     {
        String s = Double.toString(1/Double.parseDouble(textAnswer.getText()));
        textAnswer.setText(s);
        ca=true;
     }
     if (temp==F) 
     {
        vard=answerd=0;
        textAnswer.setText("");
        ca=true;
     }
    }
    catch (Exception e) 
    {
      textAnswer.setText("操作非法");
      ca=false;
    }
  }

}