我已经想出如何正确地对JTable进行排序,但我无法弄清楚如何在更改表格单元格时自动更新排序顺序.现在,我有这个(不可否认的很长)代码,主要基于
Java Tutorial的
How to Use Tables中的代码.我已经突出了我用// ADDED所做的更改.在这种情况下,新添加的值可以正确排序,但是当我进入编辑值时,即使我调用fireTableCellUpdated,它也似乎无法求助?
简而言之,当模型中的数据值发生变化时,如何让表格重新排序?
/* * Copyright (c) 1995 - 2008 Sun Microsystems,Inc. All rights reserved. * See the standard BSD license. */ package components; /* * TableSortDemo.java requires no other files. */ import java.awt.Dimension; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.ArrayList; import javax.swing.BoxLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.table.AbstractTableModel; public class TableSortDemo extends JPanel { private boolean DEBUG = false; public TableSortDemo() { super(); setLayout(new BoxLayout(TableSortDemo.this,BoxLayout.PAGE_AXIS)); final MyTableModel m = new MyTableModel(); JTable table = new JTable(m); table.setPreferredScrollableViewportSize(new Dimension(500,70)); table.setFillsViewportHeight(true); table.setAutoCreateRowSorter(true); //Create the scroll pane and add the table to it. JScrollPane scrollPane = new JScrollPane(table); //Add the scroll pane to this panel. add(scrollPane); // ADDED: button to add a value JButton addButton = new JButton("Add a new value"); addButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { m.addValue( JOptionPane.showInputDialog( TableSortDemo.this,"Value?")); } }); // ADDED button to change a value JButton setButton = new JButton("Change a value"); setButton.addActionListener(new ActionListener() { /* (non-Javadoc) * @see java.awt.event.ActionListener#actionPerformed(java.awt.event.ActionEvent) */ public void actionPerformed(ActionEvent e) { m.setValueAt( JOptionPane.showInputDialog( TableSortDemo.this,"Value?"),Integer.parseInt( JOptionPane.showInputDialog( TableSortDemo.this,"Which?")),0); } }); add(addButton); add(setButton); } class MyTableModel extends AbstractTableModel { private static final long serialVersionUID = -7053335255134714625L; private String[] columnNames = {"Column"}; // ADDED data as mutable ArrayList private ArrayList<String> data = new ArrayList<String>(); public MyTableModel() { data.add("Anders"); data.add("Lars"); data.add("Betty"); data.add("Anna"); data.add("Jon"); data.add("Zach"); } // ADDED public void addValue(Object v) { data.add(v.toString()); int row = data.size() - 1; fireTableRowsInserted(row,row); } public int getColumnCount() { return columnNames.length; } public int getRowCount() { return data.size(); } public String getColumnName(int col) { return columnNames[col]; } public Object getValueAt(int row,int col) { return data.get(row) + " " + row; } /* * JTable uses this method to determine the default renderer/ * editor for each cell. If we didn't implement this method,* then the last column would contain text ("true"/"false"),* rather than a check Box. */ public Class<String> getColumnClass(int c) { return String.class; } /* * Don't need to implement this method unless your table's * editable. */ public boolean isCellEditable(int row,int col) { //Note that the data/cell address is constant,//no matter where the cell appears onscreen. if (col < 2) { return false; } else { return true; } } /* * Don't need to implement this method unless your table's * data can change. */ public void setValueAt(Object value,int row,int col) { if (DEBUG) { System.out.println("Setting value at " + row + "," + col + " to " + value + " (an instance of " + value.getClass() + ")"); } data.set(row,value.toString()); // ADDED: uncommented this line,despite warnings to the contrary fireTableCellUpdated(row,col); if (DEBUG) { System.out.println("New value of data:"); printDebugData(); } } private void printDebugData() { int numRows = getRowCount(); int numCols = getColumnCount(); for (int i=0; i < numRows; i++) { System.out.print(" row " + i + ":"); for (int j=0; j < numCols; j++) { System.out.print(" " + data.get(i)); } System.out.println(); } System.out.println("--------------------------"); } } /** * Create the GUI and show it. For thread safety,* this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Create and set up the window. JFrame frame = new JFrame("TableSortDemo"); frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. TableSortDemo newContentPane = new TableSortDemo(); newContentPane.setOpaque(true); //content panes must be opaque frame.setContentPane(newContentPane); //Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { //Schedule a job for the event-dispatching thread: //creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } }
解决方法
这需要两个步骤:
首先,我通过使用this而不是autoCreateRowSorter对数据更改进行了TableSorter排序:
sorter = new TableRowSorter<MyTableModel>(m); table.setRowSorter(sorter); sorter.setSortsOnUpdates(true);
然后,我不得不更改更新方法以更新整个表. fireTableCellUpdated和fireTableRowsUpdated只会重绘已更新的特定行,而不是整个表(这意味着你会看到一个重复出现的条目,它会在以后重新绘制后立即更改.所以,我改变了
fireTableCellUpdated(row,col);
至
fireTableRowsUpdated(0,data.size() - 1);
现在,即使数据发生变化,它也能正确排序,并保留选择.