JTable 的实时排序 [英] Live sorting of JTable
问题描述
我已经想出了如何让 JTable 正确排序，但我不知道如何让它在表格单元格更改时自动更新排序顺序.现在，我有这个(不可否认的长)代码，主要基于 Java 教程的 如何使用表格.我已经突出显示了我对 //ADDED 所做的更改.在这种情况下，新添加的值排序正确，但是当我进入编辑值时，它似乎没有求助，即使我调用了 fireTableCellUpdated?
I've figured out how to get a JTable to be sorted properly, but I can't figure out how to get it to automatically update the sort order when a table cell is changed. Right now, I have this (admittedly long) code, mostly based on that in the Java Tutorial's How to Use Tables. I've highlighted the changes I've made with // ADDED. In this case, newly-added values sort properly, but when I go in to edit a value, it doesn't seem to resort, even though I call fireTableCellUpdated?
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?
In short, how can I get a table to re-sort when a data value changes in the model?
/*
* 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();
}
});
}
}
推荐答案
这采取了两步解决方案:
This took a two-step solution:
首先，我使用这个而不是 autoCreateRowSorter 对数据更改进行了 TableSorter 排序:
First I had the TableSorter sort on data change, by using this rather than autoCreateRowSorter:
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 只会重绘被更新的特定行，而不是整个表(这意味着你会得到一个重复出现的条目，一旦它改变后来重绘了所以，我改了
Then, I had to change the update method to update the entire table. The fireTableCellUpdated and the fireTableRowsUpdated would only redraw the specific rows that were updated, not the entire table (meaning you'd get a duplicate-appearing entry that changed as soon as it was redrawn later. So, I changed
fireTableCellUpdated(row, col);
到
fireTableRowsUpdated(0, data.size() - 1);
现在它可以正确排序，即使在数据更改时也是如此，并且选择被保留.
and now it sorts properly, even upon data changes, and selection is preserved.
这篇关于JTable 的实时排序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
