gridbaglayoutuse.java

JAVA编程思想源代码 值得一下 很难找的

package chapter11;

import java.awt.Button;
import java.awt.Color;
import java.awt.Frame;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class GridBagLayoutUse extends Frame {

	Button b1 = new Button("红"), b2 = new Button("黄"), b3 = new Button("绿");

	TextArea texta = new TextArea(3, 10);

	public GridBagLayoutUse() {
		super("GridBagLayout");
		setLayout(new GridBagLayout());
		GridBagConstraints gbc = new GridBagConstraints();
		gbc.fill = GridBagConstraints.BOTH;
		gbc.gridx = 0;
		gbc.gridy = 0;
		gbc.gridwidth = 2;
		gbc.gridheight = 2;
		gbc.weightx = 1;
		gbc.weighty = 1;
		add(b1, gbc);
		gbc.gridx = 2;
		gbc.gridy = 0;
		gbc.gridwidth = 2;
		gbc.gridheight = 2;
		gbc.weightx = 1.0;
		gbc.weighty = 1.0;
		add(texta, gbc);
		gbc.gridx = 4;
		gbc.gridy = 0;
		gbc.gridwidth = 1;
		gbc.gridheight = 1;
		gbc.weightx = 0.0;
		gbc.weighty = 0.0;
		add(b2, gbc);
		gbc.gridx = 4;
		gbc.gridy = 1;
		gbc.gridwidth = 1;
		gbc.gridheight = 1;
		gbc.weightx = 0.0;
		gbc.weighty = 0.0;
		add(b3, gbc);
		setSize(240, 150);
		setVisible(true);
		b1.addActionListener(new useListener());
		b2.addActionListener(new useListener());
		b3.addActionListener(new useListener());

	}

	class useListener implements ActionListener {
		public void actionPerformed(ActionEvent e) {

			if (e.getSource() == b1)
				texta.setBackground(Color.RED);
			else if (e.getSource() == b2)
				texta.setBackground(Color.YELLOW);
			else if (e.getSource() == b3)
				texta.setBackground(Color.GREEN);

		}
	}

	public static void main(String args[]) {
		GridBagLayoutUse use = new GridBagLayoutUse();
	}

}