一个简单的计算器

最新推荐文章于 2025-02-01 17:12:42 发布

原创最新推荐文章于 2025-02-01 17:12:42 发布 · 1k 阅读

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#button #string #import #menu #class #dialog

这是一个简单的计算器程序，使用Java Swing实现。具备基本的数学运算功能，并提供复制、粘贴等辅助功能。

java最后一次实验内容。。。

import javax.swing.*;
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.event.*;
import java.io.IOException;
public class computer implements ActionListener {
private JFrame frame=new JFrame("简单计算器");
private Panel p=new Panel();
private Panel p1=new Panel();
private Panel p2=new Panel();
private Panel p3=new Panel();
private MenuBar mb=new MenuBar();
private Button button[]=new Button[21];
private Button button1[]=new Button[4];
private Button button2[]=new Button[5];
private JTextField tf=new JTextField();
private TextField tf1=new TextField();
//定义操作数和操作符
private String str1,str2,opr;
private boolean flag=true;
//定义中间缓存变量
private double result, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
private Clipboard cb = Toolkit.getDefaultToolkit().getSystemClipboard();

public void com( )
{

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new BorderLayout(5,5));
frame.setBackground(Color.LIGHT_GRAY);
frame.setLocation(300,200);
//设置又对齐
tf.setHorizontalAlignment(SwingConstants.RIGHT);

p.setLayout(new BorderLayout(3,3));
p.setBackground(Color.lightGray);
p1.setLayout(new GridLayout(4,5));
p2.setLayout(new FlowLayout(FlowLayout.LEFT,5,0));
p3.setLayout(new GridLayout(4,1));
frame.setMenuBar(mb);
Menu m1 = new Menu("编辑(E)");
Menu m2 = new Menu("查看(V)");
Menu m3 = new Menu("帮助(H)");
    mb.add(m1);
    mb.add(m2);
    mb.add(m3);
    MenuItem mi1 = new MenuItem("复制(C)",new MenuShortcut(KeyEvent.VK_C));
MenuItem mi2 = new MenuItem("粘贴(V)",new MenuShortcut(KeyEvent.VK_V));
MenuItem mi3 = new MenuItem("退出");
MenuItem mi4 = new MenuItem("科学型(S)");
MenuItem mi5 = new MenuItem("数字分组(T)");
MenuItem mi6 = new MenuItem("关于计算器");
MenuItem mi7 = new MenuItem("帮助主题");
    mi1.addActionListener(this);
    mi2.addActionListener(this);
    mi3.addActionListener(this);
    mi4.addActionListener(this);
    mi5.addActionListener(this);
    mi6.addActionListener(this);
    mi7.addActionListener(this);

    //添加
    m1.add(mi1);
    m1.add(mi2);
    m1.addSeparator();
    m1.add(mi3);

    m2.add(mi4);
    m2.add(mi5);

    m3.add(mi6);
    m3.add(mi7);

    //定义Backspace,CE,C,""
    for(int i=1;i<4;i++)
    {
    button1[i]=new Button();
    button1[i].setFont(new Font("仿宋",0,16));
    button1[i].setBackground(Color.lightGray);
    button1[i].setForeground(Color.red);
    }
    button1[1].setLabel("Backspace");
    button1[2].setLabel("CE");
    button1[3].setLabel(" C ");
    tf1.setEnabled(false);
    p2.add(tf1);
    for(int i=1;i<4;i++)
    {
    p2.add(button1[i]);
    button1[i].addActionListener(this);
    }
    for(int i=1;i<21;i++)
    {
    button[i]=new Button();
    button[i].setFont(new Font("仿宋",0,16));
    button[i].setBackground(Color.LIGHT_GRAY);
    button[i].setForeground(Color.BLUE);
    }
    button[1].setLabel("7");
    button[2].setLabel("8");
    button[3].setLabel("9");
    button[4].setLabel("/");
    button[5].setLabel("sqrt");
    button[6].setLabel("4");
    button[7].setLabel("5");
    button[8].setLabel("6");
    button[9].setLabel("*");
    button[10].setLabel("%");
    button[11].setLabel("1");
    button[12].setLabel("2");
    button[13].setLabel("3");
    button[14].setLabel("-");
    button[15].setLabel("1/x");
    button[16].setLabel("0");
    button[17].setLabel("+/-");
    button[18].setLabel(".");
    button[19].setLabel("+");
    button[20].setLabel("=");
    for(int i=1;i<21;i++)
    {
    p1.add(button[i]);
    button[i].addActionListener(this);
    button[i].setBackground(Color.LIGHT_GRAY);
    button[i].setForeground(Color.BLUE);
    }
    for(int i=4;i<21;i=i+5)
    {
    button[i].setForeground(Color.RED);
    }
    button[20].setForeground(Color.RED);

    for(int i=1;i<5;i++)
    {
    button2[i]=new Button();
    button2[i].setFont(new Font("仿宋",0,16));
     button2[i].setBackground(Color.lightGray);
     button2[i].setForeground(Color.red);
    }

    button2[1].setLabel("MC");
    button2[2].setLabel("MR");
    button2[3].setLabel("MS");
    button2[4].setLabel("M+");

    for(int i=1;i<5;i++)
    {
    p3.add(button2[i]);
    button2[i].addActionListener(this);
    }
    frame.getContentPane().add(tf,"North");
    p.add(p1,"Center");
    p.add(p2,"North");
    p.add(p3,"West");
    frame.getContentPane().add(p,"Center");

frame.pack();
frame.setResizable(false);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
str1=e.getActionCommand();
String str3=tf.getText();
if(str1=="1"|str1=="2"|str1=="3"|str1=="4"|str1=="5"|str1=="6"|str1=="7"|str1=="8"|str1=="9"|str1=="0")
{
  if(flag)
  {
   tf.setText(str3+str1);
  }
  else
  {
   tf.setText(str1);
   flag=true;
  }
}
else if(str1=="+"|str1=="-"|str1=="*"|str1=="/")
{
  result=Double.parseDouble(tf.getText());
  flag=false;
  opr=str1;
}
else if(str1=="=")
{
  String strtmp;
  String tempstr="";
  String str0;
  int loc;
  boolean ok;
  tmp1=Double.parseDouble(tf.getText());
  if(opr=="+")result+=tmp1;
  if(opr=="-")result-=tmp1;
  if(opr=="*")result*=tmp1;
  if(opr=="/")result/=tmp1;
  strtmp=Double.toString(result);
  loc=strtmp.indexOf(".");
  str0=strtmp.substring(loc+1);
  if(Double.parseDouble(str0)==0.0)
  {
   tf.setText(strtmp.substring(0,loc));
  }
  else tf.setText(Double.toString(result));
  opr=" ";
  flag=false;
}
else if(str1=="sqrt")
{
  tmp2=Double.parseDouble(tf.getText());
  if(tmp2>0)
  {
   tmp2=Math.sqrt(Double.parseDouble(tf.getText()));
   tf.setText(Double.toString(tmp2));
   flag=false;
  }
}
else if(str1=="%")
{
  tmp3=Double.parseDouble(tf.getText())/100;
  if(opr == "*")
  {
  result = result*(result*tmp3);
  tf.setText(Double.toString(result));
  }
  else if(opr == "+")
  {
  result = result+result*tmp3;
  tf.setText(Double.toString(result));
  }
  else if(opr == "-")
  {
  result = result-result*tmp3;
  tf.setText(Double.toString(result));
  }
  else if(opr == "/")
  {
  result = result/(result*tmp3);
  tf.setText(Double.toString(result));
  }
  else
  {
  tf.setText("0.0");
  }
  flag = false;
  opr = "";
}
else if(str1=="1/x")
{
  tmp4=Double.parseDouble(tf.getText());
  result=1.0/tmp4;
  tf.setText(Double.toString(result));
  flag=false;
}
else if(str1=="+/-")
{
  tmp5=-1*Double.parseDouble(tf.getText());
  tf.setText(Double.toString(tmp5));
}
else if(str1==".")
{
  if(str3.indexOf('.')==-1)
  {
       tf.setText(str3+str1);
  }
}
else if(str1==" C ")
{
  tf.setText("0.0");
  flag=false;
}
else if(str1=="CE")
{
  tf.setText("0");
  flag=false;
}
else if(str1=="Backspace")
{
  tf.setText(str3.substring(0,(str3.length()-1)));
}
else if(str1=="MC")
{
  str2 ="";
  tf1.setText("");
}
else if(str1=="MS")
{
  String before = tf.getText();
  tmp7 = Double.parseDouble(before);
  str2 = Double.toString(tmp7);
  tf1.setText(" M");
  flag = false;
}
else if(str1=="M+")
{
  tmp7 = tmp7 + Double.parseDouble(tf.getText());
  str2 = Double.toString(tmp7);
  flag = false;
}
else if(str1=="复制(C)")
{
  String text = tf.getText();
  StringSelection selection = new StringSelection(text);
  cb.setContents(selection, null);
}
else if(str1=="粘贴(V)")
{
  Transferable contents = cb.getContents(this);
  DataFlavor flavor = DataFlavor.stringFlavor;
  try{
  String text = (String)contents.getTransferData(flavor);
  if (!text.equals(null))
  {
  tf.setText(text);
  }
  else
  {
    tf.setText("0.0");
  }
   }
  catch(UnsupportedFlavorException ef)
  {
  }
  catch(IOException ex)
  {
  }
}
else if(str1=="数字分组(T)")
{
  String str4=tf.getText();
  for(int i=1;(3*i)<str4.length();i++)
  {

  }
}
else if(str1=="关于计算器")
{
  aboutcomputer d;
  d=new aboutcomputer(frame);
    d.display();
}
else if(str1=="帮助主题")
{
  helpcomputer d;
  d=new helpcomputer(frame);
  d.display();
}
else if(str1=="退出")
{
  System.exit(1);
}
}
class pressKeyboard extends KeyAdapter
{
private JTextField tf;
public pressKeyboard(JTextField tf)
{
  this.tf=tf;
}
public void KeyTyped(KeyEvent e)
{
  String s1=tf.getText();
  char ch=e.getKeyChar();
  if(ch=='1'|ch=='2'|ch=='3'|ch=='4'|ch=='5'|ch=='6'|ch=='7'|ch=='8'|ch=='9'|ch=='0')
  {
   if(flag)
   {
    tf.setText(s1+ch);
   }
   else
   {
    tf.setText(ch+"");
    flag=true;
   }
  }
  else if(ch=='+'|ch=='-'|ch=='*'|ch=='/')
  {
   result=Double.parseDouble(tf.getText());
   flag=false;
   opr=ch+"";
  }
}
}
public static void main(String[]args)
{
computer computer1=new computer();
computer1.com();
}
}

关于

aboutcomputer.java

import java.io.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class aboutcomputer extends Dialog implements ActionListener {
private Label l;
private Label ll;
private Button b;
public TextArea ta;
private Panel p1;
private Panel p2;
private Panel p3;
private String title = "关于计算器";

public aboutcomputer(JFrame f){
  super(f,true);
  this.setTitle(title);
  l = new Label("简单计算器");
  l.setForeground(Color.blue);
  l.setFont(new Font("Arial",Font.PLAIN,24));
  ll = new Label("java最后一次实验!");
  ll.setForeground(Color.blue);
  ll.setFont(new Font("Arial",Font.PLAIN,24));
  ll.setBackground(Color.BLUE);
  b = new Button(" 确定 ");
  b.addActionListener(this); //(new ButtonHandler());
  ta = new TextArea("",30,50,TextArea.SCROLLBARS_VERTICAL_ONLY);
  ta.setText(ll.getText());
  ta.setBackground(Color.lightGray);
  ta.setEditable(false);
  ta.enable(false);
  p1 = new Panel();
  p2 = new Panel();
  p3 = new Panel();
  p2.setLayout(new BorderLayout(5,5));
  p1.setBackground(Color.lightGray);
  p2.setBackground(new Color(130,254,240,200));
  p3.setBackground(Color.lightGray);
  p1.add(l);
  p2.add(ta);
  p3.add(b);
  this.add(p1,"North");
  this.add(p2,"Center");
  this.add(p3,"South");
  this.setLocation(f.getX() + f.getWidth(), f.getY());
  this.addWindowListener(new WindowHandler());
  f.pack();
  f.setResizable(false);
  f.setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
  {
   dispose();
  }
}
public void display(){
  this.setSize(350,350);
  this.setResizable(false);
  this.setVisible(true);
}
private class WindowHandler extends WindowAdapter{
  public void windowClosing(WindowEvent e){
  dispose();
//  System.exit(1);
  }
}

}

helpcomputer.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class helpcomputer extends aboutcomputer implements ActionListener{
private String str;
private Button bt;
public helpcomputer(JFrame f)
{
  super(f);
  this.setTitle("简单计算器帮助文档!");
  str="呵呵，还没有帮助文档！";
  ta.setText(str);
  bt=new Button("确定");
}
}