buttonlocation.java

编程之道--java程序设计入门源代码

/**
 *　边界布局的效果
 */
import java.awt.Toolkit;
import java.awt.Image;
import java.awt.Dimension;
import java.awt.Container;
import java.awt.Color;
import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;


public class ButtonLocation
{
	public static void main(String[] args)
	{
		ButtonFrame frame = new ButtonFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.show();
	} 
}

/**
 *　这是定制自己的按钮框架
 */
class ButtonFrame extends JFrame
{
	private static final int WIDTH = 400;
	private static final int HEIGHT = 300;
	
	public ButtonFrame()
	{
		Container con = getContentPane();//得到了内容窗格
		
		Toolkit kit = Toolkit.getDefaultToolkit();
		Dimension screenSize = kit.getScreenSize();
		int width = screenSize.width;
		int height = screenSize.height;
		int x = (width - WIDTH)/2;
		int y = (height - HEIGHT)/2;
		setLocation(x, y);//设置坐标起点
		setSize(WIDTH, HEIGHT);//设置框架的大小
		Image image = kit.getImage("duke.gif");// duke.gif为图像文件名
		setIconImage(image);//设置框架图标
		setTitle("测试边界布局管理器的效果");//设置框架的标题
				
		ButtonPanel panel = new ButtonPanel();//得到定制的面板
		con.add(panel);//将面板添加到内容窗格中
	}
}

/**
 *　这是继承了JPanel面板类
 */
class ButtonPanel extends JPanel
{
		
	public ButtonPanel()
	{
		JButton yellow = new JButton("Yellow");
		JButton red = new JButton("Red");
		JButton black = new JButton("Black");
		JButton pink = new JButton("Pink");
		JButton green = new JButton("Green");	
		
		setLayout(new BorderLayout());
		
		//将按钮添加到面板中
		add(yellow, BorderLayout.NORTH);
		add(red, BorderLayout.WEST);		
		add(black, BorderLayout.EAST);
		add(pink, BorderLayout.SOUTH);
		add(green, BorderLayout.CENTER);		
				
		setBackground(Color.blue);//设置面板的背景颜色
	}
}