关于布局的问题
import   java.awt.*;
import   java.awt.event.*;
import   javax.swing.*;
import   javax.swing.tree.*;
public   class   yanshi   extends   JFrame
{
protected   JTree   m_tree;
Container   cp=getContentPane();
Font   f=new   Font( "TimesRoman ",Font.BOLD,24);
public   yanshi()
{
Object[]   nodes=new   Object[5];
Dimension   screen=getToolkit().getScreenSize();
cp.setLayout(new   FlowLayout(FlowLayout.LEADING));
JLabel   lb=new   JLabel( "数据结构演示系统 ",JLabel.CENTER);
lb.setPreferredSize(new   Dimension(screen.width-50,100));
lb.setFont(f);
lb.setForeground(Color.red);
lb.setBackground(Color.cyan);
cp.add(lb);
DefaultMutableTreeNode   top=new   DefaultMutableTreeNode(new   OidNode(1, "线性表 "));
DefaultMutableTreeNode   parent=top;
DefaultMutableTreeNode   node=new   DefaultMutableTreeNode(new   OidNode(0, "顺序表 "));
parent.add(node);
parent=node;
node=new   DefaultMutableTreeNode(new   OidNode(1, "插入 "));
parent.add(node);
node=new   DefaultMutableTreeNode(new   OidNode(1, "删除 "));
parent.add(node);
m_tree=new   JTree(top)
{
public   String   getToolTipText(MouseEvent   e)
{
TreePath   path=m_tree.getPathForLocation(e.getX(),e.getY());
if(path==null)   return   null;
Object[]   nodes=path.getPath();
String   oid= " ";
for(int   k=0;k <nodes.length;k++)
{
DefaultMutableTreeNode   treenode=(DefaultMutableTreeNode)nodes[k];
OidNode   nd=(OidNode)treenode.getUserObject();
oid+= ". "+nd.getId();
}
return   oid;
}
};
ToolTipManager.sharedInstance().registerComponent(m_tree);
m_tree.setShowsRootHandles(true);
m_tree.putClientProperty( "JTree.lineStyle ", "Angled ");
m_tree.setEditable(false);
m_tree.addMouseListener(new   MouseAdapter(){
public   void   mouseClicked(MouseEvent   e)
{
tvwTreeView_mouseClicked(e);
}
});
JScrollPane   s=new   JScrollPane(m_tree);
s.setPreferredSize(new   Dimension(200,600));
getContentPane().add(s,BorderLayout.CENTER);
setSize(screen.width-50,screen.height-50);
setLocation(20,10);
setVisible(true);
cp.add(s);
JTextField   tf=new   JTextField();
tf.setPreferredSize(new   Dimension(750,600));
cp.add(tf);
}
private   void   tvwTreeView_mouseClicked(MouseEvent   e)
{
TreePath   path=m_tree.getPathForLocation(e.getX(),e.getY());
if(path==null)   return;
Object[]   nodes=path.getPath();
String   oid= " ";
for(int   k=0;k <nodes.length;k++)
{
DefaultMutableTreeNode   node=(DefaultMutableTreeNode)nodes[k];
OidNode   nd=(OidNode)node.getUserObject();
oid+= ". "+nd.getName();
}
}
public   static   void   main(String   argv[])
{
yanshi   ys=new   yanshi();
ys.addWindowListener(new   WindowAdapter(){
public   void   windowClosing(WindowEvent   e)
{
System.exit(0);
}
});
}
}
class   OidNode
{
private   int   m_id;
private   String   m_name;
public   OidNode(int   id,String   name)