无法用新数据刷新我的JTable [英] Can't refresh my JTable with new data
问题描述
我最初创建框架时会创建一个JTable，但是会创建一个扩展的空AbstractTableModel.然后，用户必须从JComboBox中选择某项，并且用户可以预览处理该指定选择的消息.
I create a JTable when the frame is intially created, but create an empty AbstractTableModel which I extended. Then the user has to select something from a JComboBox and the user can preview the messages dealing with that specified selection.
单击预览按钮时，我将使用新数据创建一个新的AbstractTableModel并将该模型设置为新创建的JTable对象.完成后，我将呼叫AbstractTableModel.fireTableDataChanged，JTable.repaint()，JTable.validate() JFrame.repaint()，JFrame.validate().
When the preview button is clicked, I create a new AbstractTableModel with the new data and set that model to a newly created JTable object. Once that is done, I call AbstractTableModel.fireTableDataChanged, JTable.repaint(), JTable.validate() JFrame.repaint(), JFrame.validate().
使用所有这些调用，我仍然无法获得JTable来刷新新数据.
With all those calls, I still can't get the JTable to refresh with the new data.
我的JFrame和JTable:
My JFrame with the JTable:
public class StudentMessageViewer extends JFrame implements ActionListener {
final String CMD_DELETE = "CMD_DELETE";
final String CMD_DUMP = "CMD_DUMP";
final String CMD_MOVE = "CMD_MOVE";
final String CMD_PREVIEW = "CMD_PREVIEW";
private Students students;
private JComboBox<String> Names;
private TableModel Model;
public Selector(Students students) {
super("Main");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(new Dimension(700, 800));
setContentPane(getMainPanel());
setLocationRelativeTo(null);
setVisible(true);
}
private JPanel getMainPanel() {
JPanel main = new JPanel();
main.add(getSelectorPanel());
main.add(getTablePanel());
main.add(getButtonPanel());
return main;
}
private JPanel getSelectorPanel() {
JPanel main = new JPanel();
main.setLayout(new BoxLayout(main, BoxLayout.PAGE_AXIS));
FlowLayout flowLayout = new FlowLayout(FlowLayout.RIGHT);
main.setMaximumSize(new Dimension(450, 180));
Names = new JComboBox<String>(students.getNames());
JPanel NamesPanel = new JPanel();
NamesPanel.add(new JLabel("Name: "));
NamesPanel.add(Names);
main.add(NamesPanel);
return main;
}
private JPanel getTablePanel() {
JPanel main = new JPanel();
this.Model = new Model(new Object[0][4]);
this.MessagesTable = new JTable(this.Model);
TableColumn column = this.MessagesTable.getColumnModel().getColumn(0);
column.setPreferredWidth(20);
this.MessagesTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
this.MessagesTable.setSelectionBackground(getBackground());
this.MessagesTable.setSelectionForeground(getForeground());
main.add(new JScrollPane(this.MessagesTable));
return main;
}
private JPanel getButtonPanel() {
JPanel main = new JPanel(new FlowLayout(FlowLayout.RIGHT));
JButton btnDelete = new JButton("Delete");
JButton btnDump = new JButton("Dump");
JButton btnMove = new JButton("Move");
JButton btnPreview = new JButton("Preview");
btnDelete.setActionCommand(CMD_DELETE);
btnDump.setActionCommand(CMD_DUMP);
btnMove.setActionCommand(CMD_MOVE);
btnPreview.setActionCommand(CMD_PREVIEW);
btnDelete.addActionListener(this);
btnDump.addActionListener(this);
btnMove.addActionListener(this);
btnPreview.addActionListener(this);
main.add(btnDelete);
main.add(btnDump);
main.add(btnMove);
main.add(btnPreview);
this.getRootPane().setDefaultButton(btnPreview);
return main;
}
private void setTableData() {
Object data[][] = students.Select(Names.getSelectedItem().toString());
this.Model = new Model(data);
this.MessagesTable = new JTable(this.Model);
TableColumn column = this.MessagesTable.getColumnModel().getColumn(0);
column.setPreferredWidth(20);
this.MessagesTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
this.MessagesTable.setSelectionBackground(getBackground());
this.MessagesTable.setSelectionForeground(getForeground());
((AbstractTableModel) this.MessagesTable.getModel()).fireTableDataChanged();
this.MessagesTable.repaint();
this.repaint();
this.validate();
}
@Override
public void actionPerformed(ActionEvent event) {
String actionCmd = event.getActionCommand();
if(actionCmd.equals(CMD_DELETE))
System.out.println("DELETE");
else if(actionCmd.equals(CMD_DUMP))
System.out.println("DUMP");
else if(actionCmd.equals(CMD_MOVE))
System.out.println("MOVE");
else if(actionCmd.equals(CMD_PREVIEW))
setTableData();
}
}
我扩展了AbstractTableModel的TableModel类:
My TableModel class which I extended AbstractTableModel:
public class Model extends AbstractTableModel {
Object data[][];
String columnNames[] = { "", "Message ID", "Group ID", "DateSent", "Message"};
public Model(Object[][] data) {
this.data = new Object[data.length][columnNames.length];
for (int i = 0; i < data.length; i++) {
this.data[i][0] = Boolean.TRUE;
for (int j = 0; j < columnNames.length - 1; j++)
this.data[i][j + 1] = data[i][j];
}
}
public int getColumnCount() {
return (columnNames == null ? 0 : columnNames.length);
}
public String getColumnName(int column) {
return (columnNames == null ? "" : columnNames[column]);
}
public int getRowCount() {
return (data == null ? 0 : data.length);
}
public Object getValueAt(int row, int column) {
return (columnNames == null ? new Object() : data[row][column]);
}
@SuppressWarnings({ "unchecked", "rawtypes" })
public Class getColumnClass(int column) {
return (getValueAt(0, column).getClass());
}
public void setValueAt(Object value, int row, int column) {
data[row][column] = value;
}
public boolean isCellEditable(int row, int column) {
return (column == 0);
}
}
推荐答案
所以我知道了.在StudentMessageViewer类的setTableData()方法中，我正在创建一个全新的TableModel对象和一个全新的JTable对象，但是将这两个新对象分配给了原始变量.因此，我可能不得不执行repaint()或validate()，但我无法弄清楚.
So I figured it out. In the setTableData() method of StudentMessageViewer class, I was creating a brand new TableModel object and a brand new JTable object, but assign these two new objects to the original variable. So I might have had to do a repaint() or a validate() but I couldn't figure that out.
但是要解决此问题，我所做的是创建一个全新的TableModel对象并使用JTable.setModel()替换旧的TableModel.
But to fix it, what I did was create a brand new TableModel object and use the JTable.setModel() to replace the old TableModel.
这是修改后的方法:
private void setTableData() {
Object data[][] = students.Select(Names.getSelectedItem().toString());
this.Model = new Model(data);
TableColumn column = this.MessagesTable.getColumnModel().getColumn(0);
column.setPreferredWidth(20);
this.MessagesTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
this.MessagesTable.setSelectionBackground(getBackground());
this.MessagesTable.setSelectionForeground(getForeground());
this.MessagesTable.setModel(this.MyModel);
}
现在，我可以多次更新表.
Now I'm able update the table as many times I want.
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