flowlayoutexam.java

Java程序设计实用教程源代码 本书源代码按章分别放置在不同的文件夹中,所有程序均在JDK1.6环境下编译运行正常,除了第13章需要建立ODBC数据源之外,其他程序只要有Java运行环境即可直接运行

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class flowLayoutExam {
  JFrame jframe = new JFrame("测试布局管理器");
  Container contentPane;
  JPanel jpanel;
  FlowLayout flow;
  public static void main(String args[]) {
    flowLayoutExam testflow = new flowLayoutExam();
    testflow.testFlow();
    testflow.changeAlign();
  }
  private static void fillComponent(Container c) {
    for (int i = 0; i < 3; i++)
      c.add(new JButton("按钮" + i));
  }
  public void testFlow () {
    contentPane = jframe.getContentPane();
    jpanel = new JPanel(); // 创建一个面板容器
    fillComponent(jpanel); // 向面板容器添加组件
    contentPane.add(jpanel);
    flow = new FlowLayout(FlowLayout.CENTER);
    contentPane.setLayout(flow);
    jframe.setSize(400, 130);
    jframe.setVisible(true);
    jframe.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
  }
  public void changeAlign() { // 改变布局管理器的排列方式
    for (int i = 0; ; i++) {
      try {
        Thread.sleep(1000);
      }
      catch (Exception e) {
        e.printStackTrace();
      }
      switch (i%3) {
        case 0:
          flow.setAlignment(FlowLayout.LEFT);
          break;
        case 1:
          flow.setAlignment(FlowLayout.CENTER);
          break;
        case 2:
          flow.setAlignment(FlowLayout.RIGHT);
          break;
      }
      flow.layoutContainer(contentPane); // 重新排列各组件
    }
  }
}