使用showMessageDialog显示消息框

import java.awt.BorderLayout;

import java.awt.EventQueue;

import javax.swing.JFrame;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.UIManager;

import javax.swing.UnsupportedLookAndFeelException;

import javax.swing.border.EmptyBorder;

import com.sun.java.swing.plaf.windows.WindowsLookAndFeel;

import javax.swing.JButton;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

public class TestMessageDialog extends JFrame {

private JPanel contentPane;

/**

* Launch the application.

*/

public static
void main(String[] args) {

EventQueue.invokeLater(new Runnable() {

public
void run() {

try {

TestMessageDialog frame = new TestMessageDialog();

frame.setVisible(true);

} catch (Exception e) {

e.printStackTrace();

}

}

});

}

/**

* Create the frame.

*/

public TestMessageDialog() {

try {

UIManager.setLookAndFeel(new WindowsLookAndFeel());

} catch (UnsupportedLookAndFeelException e1) {

e1.printStackTrace();

}

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setBounds(100, 100, 450, 300);

contentPane = new JPanel();

contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

contentPane.setLayout(new BorderLayout(0, 0));

setContentPane(contentPane);

JButton btnshowmessagedialog = new JButton("显示消息框(showMessageDialog)");

btnshowmessagedialog.setFocusable(false);

//为
按钮
添加鼠标点击事件

btnshowmessagedialog.addMouseListener(new MouseAdapter() {

@Override

public
void mouseClicked(MouseEvent e) {

/**

* 直接通过静态方法调用

* 需要指定父级窗体，消息，标题，消息类型

* 返回值是 void，即不会向系统返回任何信息

* 即消息框仅仅是为了向用户传达信息

* 没有关闭消息框时，后面的主窗体是完全无法操作的（即
阻塞）

*/

JOptionPane.showMessageDialog(TestMessageDialog.this,

"NullPointerException","Error", JOptionPane.ERROR_MESSAGE);

}

});

contentPane.add(btnshowmessagedialog, BorderLayout.NORTH);

}

}