Swing设计JDialog

在Java Swing编程中，程序员还可以自定义对话框，一般可以从JDialog类来继承。下面给出一个对话框类的代码：

class HelpAbout extends JDialog implements ActionListener

{

JavaWord mainFrame;

JButton okButton;

javax.swing.Timer myTimer;

int Counter=0;

public HelpAbout(JavaWord mainFrame)

{

super(mainFrame,"关于本程序的说明",true); //true 代表为有模式对话框

this.mainFrame= mainFrame;

JPanel contentPanel=new JPanel();

contentPanel.setLayout(new BorderLayout());

JLabel imageLabel=new JLabel(new ImageIcon(".\\images\\javalogo.gif"));

contentPanel.add(imageLabel,BorderLayout.WEST);

JPanel authorInfoPane=new JPanel();

authorInfoPane.setLayout(new GridLayout(1,1));

JTextArea aboutContent=new JTextArea("本程序是作者在学习Java2 Swing编程的一个简单的程序，\n并不作为商业目的使用。");

aboutContent.enable(false);

authorInfoPane.add(aboutContent);

contentPanel.add(authorInfoPane,BorderLayout.NORTH);

JPanel sysInfoPane=new JPanel();

sysInfoPane.setLayout(new GridLayout(5,1));

sysInfoPane.setBorder(BorderFactory.createLoweredBevelBorder());

contentPanel.add(sysInfoPane,BorderLayout.CENTER);

JLabel userName=new JLabel("本机的用户名为："+System.getProperty("user.name"));

JLabel osName=new JLabel("本机的操作系统是："+System.getProperty("os.name"));

JLabel javaVersion=new JLabel("本机中所安装的Java SDK的版本号是："+System.getProperty("java.version"));

JLabel totalMemory=new JLabel("本机中Java虚拟机所可能使用的总内存数："+Runtime.getRuntime().totalMemory()+"字节数" );

JLabel freeMemory=new JLabel("本机中Java虚拟机所剩余的内存数?quot;+Runtime.getRuntime().freeMemory()+"字节数" );

sysInfoPane.add(userName);

sysInfoPane.add(osName);

sysInfoPane.add(javaVersion);

sysInfoPane.add(totalMemory);

sysInfoPane.add(freeMemory);

JPanel OKPane=new JPanel();

okButton=new JButton("确定（O）",new ImageIcon(".\\images\\ok.gif"));

okButton.setMnemonic('O'); //设置快捷键为"Alt + O"

/*以下代码是设置案钮的Rollover图象*/

Icon rollover = new ImageIcon(".\\images\\exit.gif");

Icon general = new ImageIcon(".\\images\\ok.gif");

Icon press = new ImageIcon(".\\images\\help.gif");

okButton.setRolloverEnabled(true);

okButton.setIcon(general); //设置离开时的图象

okButton.setRolloverIcon(rollover); //设置在按纽上时的图象

okButton.setPressedIcon(press); //设置在按下按纽时的图象

this.getRootPane().setDefaultButton(okButton); //设置该按钮为该对话框的默认的按钮?.

okButton.addActionListener(this);

OKPane.add(okButton);

contentPanel.add("South",OKPane);

setContentPane(contentPanel);

// this.setResizable(false); //设置对话框为不可改变大小

myTimer=new javax.swing.Timer(1000,this);

myTimer.start();

}

public void actionPerformed(ActionEvent parm1)

{

// TODO: Add your code here

if(parm1.getSource()==okButton)

{

dispose();

}

else if(parm1.getSource()==myTimer)

{

Counter++;

this.setTitle("当前的定时器的值为:"+Counter+"秒");

}

}

}

在事件响应代码中显示出该对话框，其程序代码如下：

HelpAbout aboutDialog=new HelpAbout(this);

aboutDialog.setSize(500,500);

aboutDialog.show();