这个问题很具体。下面的代码是从 Oracle JTable 教程中提取的示例，其中添加了用于选择和取消选择最后一列中所有复选框的全选复选框的代码。我分配到的程序使用与此非常相似的设置。这是一个工作示例，但有一个问题我不知道如何解决。
当您选择/聚焦表格最后一列中的一个单元格并按下 Alt+A(“全选”复选框的助记键)时，聚焦的单元格不会呈现/与另一个单元格一起更新列中的单元格。潜在的问题是:该列是可编辑的，似乎当按下字符键时它会扰乱单元格的更新能力。如果您将单元格设置为不可编辑并在它处于焦点时使用助记符，它会工作得很好，但是您不能用鼠标单击它。
我希望既能使用鼠标单击任何复选框单元格或全选按钮，又能随时使用助记键选择全选按钮。
如果焦点位于复选框列中的单元格上，如何在使用助记符进行全选时更新复选框单元格？
这是完整的示例程序。
/*
* Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle or the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* TableDemo.java requires no other files.
*/
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableModel;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
/**
* TableDemo is just like SimpleTableDemo, except that it
* uses a custom TableModel.
*/
public class TestJTable extends JPanel {
private static final long serialVersionUID = 1L;
public static JTable table;
private boolean DEBUG = false;
public JPanel tablePanel;
public TestJTable() {
super(new GridLayout(1,0));
table = new JTable(new MyTableModel());
table.setPreferredScrollableViewportSize(new Dimension(500, 70));
table.setFillsViewportHeight(true);
//Create the scroll pane and add the table to it.
JScrollPane scrollPane = new JScrollPane(table);
JPanel selectAllCheckBoxPanel = new CreateSelectAllCheckBox();
tablePanel = new JPanel();
tablePanel.setLayout(new BorderLayout());
tablePanel.add(selectAllCheckBoxPanel, BorderLayout.PAGE_START);
tablePanel.add(scrollPane, BorderLayout.PAGE_END);
add(tablePanel);
}
class MyTableModel extends AbstractTableModel {
private static final long serialVersionUID = 1L;
private String[] columnNames = {"First Name",
"Last Name",
"Sport",
"# of Years",
"Vegetarian"};
private Object[][] data = {
{"Kathy", "Smith",
"Snowboarding", new Integer(5), new Boolean(false)},
{"John", "Doe",
"Rowing", new Integer(3), new Boolean(true)},
{"Sue", "Black",
"Knitting", new Integer(2), new Boolean(false)},
{"Jane", "White",
"Speed reading", new Integer(20), new Boolean(true)},
{"Joe", "Brown",
"Pool", new Integer(10), new Boolean(false)}
};
public int getColumnCount() {
return columnNames.length;
}
public int getRowCount() {
return data.length;
}
public String getColumnName(int col) {
return columnNames[col];
}
public Object getValueAt(int row, int col) {
return data[row][col];
}
/*
* 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 <?> getColumnClass(int c) {
return getValueAt(0, c).getClass();
}
/*
* 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[row][col] = value;
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[i][j]);
}
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("TableDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
TestJTable newContentPane = new TestJTable();
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) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
/**
* code to create the Select All check box at top of table.
*/
class CreateSelectAllCheckBox extends JPanel {
private static final long serialVersionUID = 1L;
public static JCheckBox selectAllCheckBox;
public CreateSelectAllCheckBox() {
selectAllCheckBox = new JCheckBox("Select All");
selectAllCheckBox.setFocusable(true);
selectAllCheckBox.setEnabled(true);
selectAllCheckBox.setSelected(false);
selectAllCheckBox.setOpaque(true);
selectAllCheckBox.setMnemonic(KeyEvent.VK_A);
selectAllCheckBox.addActionListener(new SelectAllActionListener());
this.setLayout(new BorderLayout());
this.add(selectAllCheckBox, BorderLayout.PAGE_START);
}
}
/**
* Listener for Select All check box. Will select all or unselect all check boxes in column 5 when toggled.
*/
class SelectAllActionListener implements ActionListener {
private static JTable table = TestJTable.table;
public void actionPerformed(ActionEvent e) {
if (CreateSelectAllCheckBox.selectAllCheckBox.isSelected()){
TableModel model = table.getModel();
for (int row = 0; row < model.getRowCount(); row++) {
model.setValueAt(Boolean.valueOf(true), row, 4);
}
}
if (!CreateSelectAllCheckBox.selectAllCheckBox.isSelected()){
TableModel model = table.getModel();
for (int row = 0; row < model.getRowCount(); row++) {
model.setValueAt(Boolean.valueOf(false), row, 4);
}
}
}
}
编辑以下——问题已解决，将 Listener 类更改为以下代码。附加代码是在设置值之前调用 cancelCellEditing()。在使用监听器设置值后，它不会阻止单元格仍然可编辑。感谢 Dodd10x 的代码:)
/**
* Listener for Select All check box. Will select all or unselect all check boxes in column 5 when toggled.
*/
class SelectAllActionListener implements ActionListener {
private static JTable table = TestJTable.table;
public void actionPerformed(ActionEvent e) {
TableCellEditor editor = table.getCellEditor();
if (editor != null) {
editor.cancelCellEditing();
}
if (CreateSelectAllCheckBox.selectAllCheckBox.isSelected()){
TableModel model = table.getModel();
for (int row = 0; row < model.getRowCount(); row++) {
model.setValueAt(Boolean.valueOf(true), row, 4);
}
}
if (!CreateSelectAllCheckBox.selectAllCheckBox.isSelected()){
TableModel model = table.getModel();
for (int row = 0; row < model.getRowCount(); row++) {
model.setValueAt(Boolean.valueOf(false), row, 4);
}
}
}
}
最佳答案
您选择的单元格处于编辑状态，因此不会更新。在全选/取消全选命令中，需要先获取当前选中的单元格，并告诉它停止编辑。
TableCellEditor editor = getCellEditor();
if (editor != null) {
editor.cancelCellEditing();
}
关于java - 如何让 JTable 复选框单元格更新为外部全选按钮助记符，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33086102/