JavaBean实例.doc

JavaBean的编程实例：设计一个包含有一个Label和三个Button的Panel Beans （1）第一步：创建出Bean Bean的程序代码 import java.awt.*; import java.awt.event.*; import java.util.*; /** * 设计一个包含有一个Label和三个Button的Panel Beans */ public class YesNoPanel extends Panel { // bean的属性 protected String messageText; // The message to display protected String yesLabel; // Text for the yes, no, cancel buttons protected String noLabel; protected String cancelLabel; // Beans的内部组件 protected Button yes, no, cancel; protected Label message; /** The no-argument bean constructor, with default property values */ public YesNoPanel() { this(Your Message Here); } public YesNoPanel(String messageText) { this(messageText, Yes, No, Cancel); } public YesNoPanel(String messageText, String yesLabel, String noLabel, String cancelLabel) { super(); //通过调用基类的构造函数，以获得Panel的一般特性 this.messageText=messageText; // The message to display this.yesLabel=yesLabel; // Text for the yes, no, cancel buttons this.noLabel=noLabel; this.cancelLabel=cancelLabel; this.setLayout(new BorderLayout(15, 15)); // Put the message label in the middle of the window. message = new Label(messageText); add(message, BorderLayout.CENTER); // Create a panel for the Panel buttons and put it at the bottom // of the Beans Panel. Specify a FlowLayout layout manager for it. Panel buttonPanel = new Panel(); buttonPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 25, 15)); this.add(buttonPanel, BorderLayout.SOUTH); // Create each specified button, specifying the action listener // and action command for each, and adding them to the buttonbox yes = new Button(); // Create buttons no = new Button(); cancel = new Button(); this.setYesLabel(yesLabel); this.setNoLabel(noLabel); this.setCancelLabel(cancelLabel); // Add the buttons to the button box buttonPanel.add(yes); buttonPan