这是一段Java Swing 的代码import java.awt.*;
import java.awt.event.*;
import javax.swing.*;public class ToolbarFrame2 extends Frame{ // This time, let's use JButtons!
JButton cutButton, copyButton, pasteButton;
JButton javaButton, macButton, motifButton, winButton; public ToolbarFrame2( ) {
super("Toolbar Example (Swing)");
setSize(450, 250); addWindowListener(new WindowAdapter( ) {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}); ActionListener printListener = new ActionListener( ) {
public void actionPerformed(ActionEvent ae) {
System.out.println(ae.getActionCommand( ));
}
};
// JPanel works similarly to Panel, so we'll use it.
JPanel toolbar = new JPanel( );
toolbar.setLayout(new FlowLayout(FlowLayout.LEFT)); cutButton = new JButton("Cut");
cutButton.addActionListener(printListener);
toolbar.add(cutButton); copyButton = new JButton("Copy");
copyButton.addActionListener(printListener);
toolbar.add(copyButton); pasteButton = new JButton("Paste");
pasteButton.addActionListener(printListener);
toolbar.add(pasteButton); add(toolbar, BorderLayout.NORTH);
// Add the L&F controls.
JPanel lnfPanel = new JPanel( );
LnfListener lnfListener = new LnfListener(this); macButton = new JButton("Mac");
macButton.addActionListener(lnfListener);
lnfPanel.add(macButton);
javaButton = new JButton("Metal");
javaButton.addActionListener(lnfListener);
lnfPanel.add(javaButton);
motifButton = new JButton("Motif");
motifButton.addActionListener(lnfListener);
lnfPanel.add(motifButton);
winButton = new JButton("Windows");
winButton.addActionListener(lnfListener);
lnfPanel.add(winButton);
add(lnfPanel, BorderLayout.SOUTH);
} public static void main(String args[]) {
ToolbarFrame2 tf2 = new ToolbarFrame2( );
tf2.setVisible(true);
}
}请问红色区域为什么错了
Eclipse提示LnfListener cannot be resolved to a type
是不是没有包括这个类库?
import java.awt.event.*;
import javax.swing.*;public class ToolbarFrame2 extends Frame{ // This time, let's use JButtons!
JButton cutButton, copyButton, pasteButton;
JButton javaButton, macButton, motifButton, winButton; public ToolbarFrame2( ) {
super("Toolbar Example (Swing)");
setSize(450, 250); addWindowListener(new WindowAdapter( ) {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}); ActionListener printListener = new ActionListener( ) {
public void actionPerformed(ActionEvent ae) {
System.out.println(ae.getActionCommand( ));
}
};
// JPanel works similarly to Panel, so we'll use it.
JPanel toolbar = new JPanel( );
toolbar.setLayout(new FlowLayout(FlowLayout.LEFT)); cutButton = new JButton("Cut");
cutButton.addActionListener(printListener);
toolbar.add(cutButton); copyButton = new JButton("Copy");
copyButton.addActionListener(printListener);
toolbar.add(copyButton); pasteButton = new JButton("Paste");
pasteButton.addActionListener(printListener);
toolbar.add(pasteButton); add(toolbar, BorderLayout.NORTH);
// Add the L&F controls.
JPanel lnfPanel = new JPanel( );
LnfListener lnfListener = new LnfListener(this); macButton = new JButton("Mac");
macButton.addActionListener(lnfListener);
lnfPanel.add(macButton);
javaButton = new JButton("Metal");
javaButton.addActionListener(lnfListener);
lnfPanel.add(javaButton);
motifButton = new JButton("Motif");
motifButton.addActionListener(lnfListener);
lnfPanel.add(motifButton);
winButton = new JButton("Windows");
winButton.addActionListener(lnfListener);
lnfPanel.add(winButton);
add(lnfPanel, BorderLayout.SOUTH);
} public static void main(String args[]) {
ToolbarFrame2 tf2 = new ToolbarFrame2( );
tf2.setVisible(true);
}
}请问红色区域为什么错了
Eclipse提示LnfListener cannot be resolved to a type
是不是没有包括这个类库?
如果本来就没有LnfListener类的代码,那么你还需要自己创建一个类,从名字上来看这是一个侦听器,需要从ActionListener里面继承。
LnfListener类不是Swing中自带的吗?
我还以为是他自己自带的
我是看那个Java Swing的那本书上的代码