尝试创建自定义JTable结构时，我从一个非常简单的项目开始，以便更好地理解。不幸的是，一旦我开始定制东西，我会得到奇怪的行为，我希望你帮助我理解它们。非常感谢你。
这是我的小项目：
public class Tableau extends JFrame {
public Tableau() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(800,600);
setContentPane(new Panel());
setVisible(true);
}
public static void main(String[] args) {
new Tableau();
}
private static class Panel extends JPanel {
private JTable table = new Table(4, 4);
public Panel() {
add(table);
}
}
private static class Table extends JTable {
private Renderer randerer = new Renderer();
public Table(int row, int col) {
super(new Model(row, col));
setAutoResizeMode(AUTO_RESIZE_OFF);
setDefaultRenderer(String.class, randerer);
setDefaultEditor(String.class, randerer);
}
private class Renderer implements TableCellRenderer, TableCellEditor {
String previousContent = "";
JTextPane rendererComponent = new JTextPane();
public Renderer() {
super();setOpaque(true);
}
@Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
rendererComponent.setText((String)value);
rendererComponent.setBorder(hasFocus ? BorderFactory.createLineBorder(Color.RED) : null);
rendererComponent.setBackground(isSelected ? Color.PINK : Color.GREEN);
FontMetrics fm = rendererComponent.getFontMetrics(rendererComponent.getFont());
if(((String)value).length()!=0) {rendererComponent.setPreferredSize(new Dimension(fm.stringWidth((String)value),fm.getHeight()));}
else {rendererComponent.setPreferredSize(new Dimension(20, fm.getHeight()));}
return rendererComponent;
}
@Override
public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
rendererComponent.setText((String)value);
rendererComponent.setBackground(isSelected ? table.getSelectionBackground() : Color.MAGENTA);
if(isSelected) {rendererComponent.selectAll();}
previousContent = (String)value;
return rendererComponent;
}
@Override
public Object getCellEditorValue() {
return rendererComponent.getText();
}
@Override
public boolean isCellEditable(EventObject anEvent) {
return true;
}
@Override
public boolean shouldSelectCell(EventObject anEvent) {
return true;
}
@Override
public boolean stopCellEditing() {
fireEditingStoppedEvent();
return true;
}
@Override
public void cancelCellEditing() {
rendererComponent.setText(previousContent);
fireEditingCanceledEvent();
}
protected void fireEditingStoppedEvent() {
for(CellEditorListener l : listeners) {l.editingStopped(new ChangeEvent(this));}
}
protected void fireEditingCanceledEvent() {
for(CellEditorListener l : listeners) {l.editingCanceled(new ChangeEvent(this));}
}
private List<CellEditorListener> listeners = new LinkedList<CellEditorListener>();
@Override
public void addCellEditorListener(CellEditorListener l) {
listeners.add(l);
}
@Override
public void removeCellEditorListener(CellEditorListener l) {
listeners.remove(l);
}
}
}
private static class Model implements TableModel {
// private ColumnModel colonnes = new ColumnModel();
private List<List<Cellule>> colonnes = new LinkedList<List<Cellule>>();
private int rowCount = 0;
// private List<Cellule> cellules = new LinkedList<Cellule>();
private static class Cellule {
public Cellule() {}
public Cellule(Object content) {this.content = content;}
private Object content;
private Object getContent() {return content;}
private void setContent(Object newContent) {content = newContent;}
}
public Model(int row, int col) {
for(int j=0; j<col; j++) {
insertColumn(j);
}
for(int i=0; i<row; i++) {
insertRow(i);
}
}
@Override
public int getRowCount() {
return rowCount;
}
@Override
public int getColumnCount() {
return colonnes.size();
}
@Override
public String getColumnName(int columnIndex) {
String result = "";
for (; columnIndex >= 0; columnIndex = columnIndex / 26 - 1) {
result = (char)((char)(columnIndex%26)+'A') + result;
}
return result;
}
@Override
public Class<?> getColumnClass(int columnIndex) {
return colonnes.isEmpty() ? Object.class : getValueAt(columnIndex, 0).getClass();
}
@Override
public boolean isCellEditable(int rowIndex, int columnIndex) {
return true;
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
return colonnes.get(columnIndex).get(rowIndex).getContent();
}
@Override
public void setValueAt(Object aValue, int rowIndex, int columnIndex) {
colonnes.get(columnIndex).get(rowIndex).setContent(aValue);
fireTableChanged(new TableModelEvent(this, rowIndex, rowIndex, columnIndex, TableModelEvent.UPDATE));
}
protected void fireTableChanged(TableModelEvent e) {
for(TableModelListener l : listeners) {
l.tableChanged(null);
}
}
public void insertColumn(int index) {
List<Cellule> newColumn = new LinkedList<Cellule>();
for(int i = 0; i<getRowCount(); i++) {
Cellule newCell = new Cellule("");
newColumn.add(newCell);
}
colonnes.add(index, newColumn);
fireTableChanged(new TableModelEvent(this, 0, getRowCount(), index, TableModelEvent.INSERT));
}
public void insertRow(int index) {
for(List<Cellule> colonne : colonnes) {
Cellule newCell = new Cellule("");
colonne.add(index, newCell);
}
rowCount++;
fireTableChanged(new TableModelEvent(this, index, index, TableModelEvent.ALL_COLUMNS, TableModelEvent.INSERT));
}
public void removeColumn(int index) {
colonnes.remove(index);
fireTableChanged(new TableModelEvent(this, 0, getRowCount(), index, TableModelEvent.DELETE));
}
public void removeRow(int index) {
for(List<Cellule> row : colonnes) {
row.remove(index);
}
rowCount--;
fireTableChanged(new TableModelEvent(this, index, index, TableModelEvent.ALL_COLUMNS, TableModelEvent.DELETE));
}
private List<TableModelListener> listeners = new LinkedList<TableModelListener>();
@Override
public void addTableModelListener(TableModelListener l) {
listeners.add(l);
}
@Override
public void removeTableModelListener(TableModelListener l) {
listeners.remove(l);
}
}
}
基本上，我们有一个JFrame（类Tableau），包含一个包含JTable（类Table）的JPanel（类Panel）。此表使用TableModel（类Model）和JTextPane（类Renderer），它们将用于呈现和编辑表内容。
以下是我的问题：
1）如果我单击一个单元格，它将变为白色（我不明白给定渲染器的代码可能如何...）。如果我写了一些内容，首先，单元格中没有任何内容，但是当我移动焦点时，文本会出现......
2）如果我单击一个单元格然后使用箭头键移动焦点，则只有这些选择似乎正确完成。正确显示红色边框等。当我单击时，为什么选择不正确而不使用箭头？
谢谢！