corejava第7版

corejava第7版/v1/v1ch11/BuggyButtonTest/BuggyButtonPanel.java

@@ -0,0 +1,43 @@
+/**
+   @version 1.21 2002-07-06
+   @author Cay Horstmann
+*/
+
+import java.awt.*;
+import java.awt.event.*;
+import javax.swing.*;
+
+class BuggyButtonPanel extends JPanel 
+{  
+   public BuggyButtonPanel()
+   {  
+      ActionListener listener = new ButtonListener();
+
+      JButton yellowButton = new JButton("Yellow");
+      add(yellowButton);
+      yellowButton.addActionListener(listener); 
+
+      JButton blueButton = new JButton("Blue");
+      add(blueButton);
+      blueButton.addActionListener(listener); 
+
+      JButton redButton = new JButton("Red");
+      add(redButton);
+      redButton.addActionListener(listener);
+   }
+
+   private class ButtonListener implements ActionListener
+   {   
+      public void actionPerformed(ActionEvent event)
+      {
+         String arg = event.getActionCommand();
+         if (arg.equals("yellow"))
+            setBackground(Color.yellow);
+         else if (arg.equals("blue")) 
+            setBackground(Color.blue);
+         else if (arg.equals("red")) 
+            setBackground(Color.red);
+      }
+   }
+}  
+