《Java程序设计》第16周周四：GUI编程及文件对话框的使用 计算器

import java.awt.Frame;
import java.awt.Button;
import java.awt.Label;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.FlowLayout;
import java.awt.TextField;
import java.awt.TextArea;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Color;
import java.lang.Exception;
public class ChatServer  implements ActionListener
{
private Frame  Fm  = new Frame();
private Button quit = new Button("退出");
private Button Add = new Button("+");
private Button Sub = new Button("-");
private Button Mul = new Button("×");
private Button Div = new Button("÷");
private Label  Addend = new Label("操作数1：");
private Label  Augend = new Label("操作数2：");
private Label  Sum      = new Label("结果：");
private TextField fieldAdd = new TextField();
private TextField fieldAug = new TextField();
private TextArea areaSum = new TextArea();
private Font Ft = new Font("宋体",Font.BOLD,18);
public ChatServer()
{
Fm.setTitle("TYH号计算器");
Fm.setBounds(200,100,400,300);
Fm.setLayout(new FlowLayout(FlowLayout.LEFT,20,20));
Fm.add(Addend);//标签--操作数1
Addend.setFont(Ft);//字体类型
Addend.setForeground(Color.black);//设置字体颜色
Addend.setPreferredSize(new Dimension(100,30));//设置组件尺寸
Fm.add(fieldAdd);//输入区--操作数1
fieldAdd.setPreferredSize(new Dimension(100,30));//设置组件尺寸
fieldAdd.setFont(Ft);//字体类型
fieldAdd.setForeground(Color.black);
Fm.add(Add);
Add.addActionListener(this);

Fm.add(Sub);
Sub.addActionListener(this);
Fm.add(Augend);//标签--操作数2
Augend.setFont(Ft);
Augend.setForeground(Color.black);
Augend.setPreferredSize(new Dimension(100,30));//设置组件尺寸
Fm.add(fieldAug);//输入区--操作数2
fieldAug.setPreferredSize(new Dimension(100,30));//设置组件尺寸
fieldAug.setFont(Ft);
fieldAug.setForeground(Color.black);
Fm.add(Mul);
Mul.addActionListener(this);
Fm.add(Div);
Div.addActionListener(this);
Fm.add(Sum);//标签--结果
Sum.setFont(Ft);
Sum.setForeground(Color.black);
Sum.setPreferredSize(new Dimension(100,30));//设置组件尺寸
Fm.add(areaSum);
areaSum.setPreferredSize(new Dimension(100,30));//设置组件尺寸
areaSum.setFont(Ft);
areaSum.setForeground(Color.red);
Fm.add(quit);
quit.addActionListener(this);
Fm.setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
try
{
if(e.getSource()==quit)
System.exit(0);
else if(e.getSource()==Add)
areaSum.setText(Double.toString(Double.parseDouble(fieldAdd.getText()) + Double.parseDouble(fieldAug.getText())));
else if(e.getSource()==Sub)

areaSum.setText(Double.toString(Double.parseDouble(fieldAdd.getText()) -  Double.parseDouble(fieldAug.getText())));
else if(e.getSource()==Mul)
areaSum.setText(Double.toString(Double.parseDouble(fieldAdd.getText()) *  Double.parseDouble(fieldAug.getText())));
else if(e.getSource()==Div)
areaSum.setText(Double.toString(Double.parseDouble(fieldAdd.getText()) /  Double.parseDouble(fieldAug.getText())));
}
catch(Exception Ex)
{
areaSum.setText("出错了："+Ex);
}
}
public static void main(String args[])
{
ChatServer call = new ChatServer();
}

}