我有以下实现 3 个 JPanel 的类。1 面板有一个标签,接下来是按钮,第三个是我的代码中描述的表格:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.table.*;
import java.util.*;
import javax.swing.event.*;
class netTable implements ActionListener, TableModelListener
{
JFrame frame;
JTable table;
Vector rows,columns;
DefaultTableModel tabModel;
JScrollPane scrollPane;
JLabel lblMessage;
JButton cmdLookup, cmdUpdatePlan;
JPanel topPanel,mainPanel,buttonPanel;
public static void main(String[] args)
{
netTable t=new netTable();
}
netTable()
{
rows=new Vector();
columns= new Vector();
String[] columnNames =
{
"ID",
"Client",
"Plan",
"Amount"
};
addColumns(columnNames);
tabModel=new DefaultTableModel();
tabModel.setDataVector(rows,columns);
table = new JTable(tabModel);
scrollPane= new JScrollPane(table);//ScrollPane
table.setRowSelectionAllowed(false);
table.getModel().addTableModelListener(this);
topPanel = new JPanel();
lblMessage=new JLabel("Invoices to Update");
topPanel.add(lblMessage);
buttonPanel=new JPanel();
cmdLookup=new JButton("Lookup");
cmdUpdatePlan = new JButton("Update Plan");
buttonPanel.add(cmdLookup);
buttonPanel.add(cmdUpdatePlan);
cmdLookup.addActionListener(this);
cmdUpdatePlan.addActionListener(this);
mainPanel=new JPanel();
frame=new JFrame("Update Table");
frame.setSize(500,500);
frame.setExtendedState(JFrame.ICONIFIED);
mainPanel.setLayout(new BorderLayout());
mainPanel.add(topPanel,BorderLayout.NORTH);
mainPanel.add(buttonPanel,BorderLayout.CENTER);
mainPanel.add(scrollPane,BorderLayout.SOUTH);
topPanel.setBackground(Color.gray);
mainPanel.setBackground(Color.white);
buttonPanel.setBackground(Color.white);
table.getParent().setBackground(Color.black);
frame.getContentPane().add(mainPanel);
frame.addWindowListener(new WindowCloser());
frame.setVisible(true);
}
}
当我编译它时,它会在顶部显示 buttonPanel、一个空格,然后在其下方显示 scrollPane,而忽略 topPanel 应该首先在顶部显示的标签。有任何想法吗?我认为 BorderLayout 位置是错误的。