请教高手。

dylsz 2003-10-17 10:05:19

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ControlPane extends JInternalFrame {
Component right, left, bottom;
JSplitPane top, total;

public ControlPane(String title, boolean b1, boolean b2, boolean b3, boolean b4){
super(title, b1, b2, b3, b4);
setBounds(0, 0, 550, 350);
Dimension minsize = new Dimension(250, 250);
bottom = new MyPanel2();
right = new MyPanel1(bottom);
left = new MyPanel3();
top = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, right, left);
top.setDividerSize(6);
top.setMinimumSize(minsize);

bottom.setVisible(false);
total = new JSplitPane(JSplitPane.VERTICAL_SPLIT, top , bottom);
total.setDividerSize(6);

getContentPane().add(total, BorderLayout.CENTER);

}
}

class MyPanel1 extends JPanel{
Component c;

public MyPanel1(Component c){
this.c = c;
Action show = new AbstractAction("sure"){
public void actionPerformed(ActionEvent e)
{
c.setVisible(true);
}
};
JButton sure = new JButton(show);
add(sure);
}

public Dimension getMinimumSize(){
return new Dimension(50, 300);
}
}

class MyPanel2 extends JPanel{

public Dimension getPreferredSize()
{
return new Dimension(200, 20);
}
}

class MyPanel3 extends JPanel{
}

我想把窗口分成3部分，下面部分开始时隐藏。第一部分有个按钮，按此按钮下面部分显示。

运行时出现如下提示：
E:\java\soft\ControlPane.java:37: local variable c is accessed from within inner class; needs to be declared final
c.setVisible(true);

这是为什么啊。

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