java - 无法使用 Jtextfields 添加焦点监听器或在 Jtable 中设置字体

Question

我正在尝试使用 Jtable 显示数据(英语和非英语语言的组合)。由于我也有非英语数据，我尝试为每个单元格(jtextfield)设置字体。我还想在 Jtable 中渲染后编辑数据，但我无法实现(即，未调用 focusgained() 中的代码)jtext 字段上的焦点监听器事件。

我使用以下渲染器在 jtable 中显示数据，并将每个单元格作为文本字段

DefaultTableCellRenderer renderer = new DefaultTableCellRenderer() {

                @Override
                public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
                    JTextField tf=new JTextField();
                    if (value != null) {
                        if (value.startsWith("_")) {
            value=value.substring(1);
                            tf.setFont(fntEng);
                        } else if (fnt_Local != null && fnt_Local.canDisplayUpTo(value.toString()) == -1) {
                            tf.setFont(fnt_Local);
                        }
                        setText(value.toString());
                    } else {
                        tf.setFont(fnt_Local);
                        tf.setText((String) value);
                    }
                    tf.setForeground(Color.BLACK);
                    tf.setBackground(Color.WHITE);
                    tf.setText(value.toString());
                    tf.addFocusListener(new FocusListener() {

                        public void focusGained(FocusEvent e) {
                     JTextField tf1=(JTextField)e.getComponent();
                     tf1.setText("Focusgained");
                        }

                        public void focusLost(FocusEvent e) {

                        }
                    });

                    return tf;
                }
            }; 

Answer 1

如果我正确理解你的问题，你只需要在编辑时使用相同的字体以及重新渲染的字体。而且您无法让编辑器正常工作。

首先...

不要混淆编辑器和渲染器的概念。渲染应该留给渲染器，编辑应该留给编辑器。如需进一步阅读，请参阅See How to use Tables: Editors and Renderers

至于你的情况...

渲染

不需要自定义渲染器来完成像设置字​​体这样简单的事情。只需覆盖 prepareRenderer 即可。您可以使用 column 值来确定哪一列应使用哪种字体。例如

JTable table = new JTable(data, cols) {
    @Override
    public Component prepareRenderer(TableCellRenderer renderer, int row, int col) {
        Component c = super.prepareRenderer(renderer, row, col);
        if (col == IMPACT_COL) {
            c.setFont(IMPACT_FONT);
        } else if (col == ARIAL_COL) {
            c.setFont(ARIAL_BOLD_FONT);
        }
        return c;
    }
};

编辑

只需将字体设置为文本字段，然后为所需的列设置新的单元格编辑器，使其与您选择用于渲染列的字体相匹配。这样，您将在编辑时看到相同的渲染字体。像这样的东西:

private static final int IMPACT_COL = 0;
private static final Font IMPACT_FONT = new Font("impact", Font.PLAIN, 20);
...
JTextField impactField = getFontEditorField(IMPACT_FONT);
TableColumn impactColumn = table.getColumnModel().getColumn(IMPACT_COL);
impactColumn.setCellEditor(new DefaultCellEditor(impactField));
...
public JTextField getFontEditorField(Font font) {
    JTextField field = new JTextField();
    field.setFont(font);
    return field;
}

完整示例

import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;

import javax.swing.DefaultCellEditor;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;

public class ChangeFontInEditorDemo {
    private static final int IMPACT_COL = 0;
    private static final int ARIAL_COL = 1;
    private static final Font IMPACT_FONT = new Font("impact", Font.PLAIN, 20);
    private static final Font ARIAL_BOLD_FONT = new Font("arial", Font.BOLD, 20);

    public ChangeFontInEditorDemo() {
        JFrame frame = new JFrame();
        frame.add(new JScrollPane(getTable()));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    private JTable getTable() {
        String[][] data = { { "Data", "Data" }, { "Data", "Data" } };
        String[] cols = { "Col", "Col" };
        JTable table = new JTable(data, cols) {
            @Override
            public Component prepareRenderer(TableCellRenderer renderer, int row, int col) {
                Component c = super.prepareRenderer(renderer, row, col);
                if (col == IMPACT_COL) {
                    c.setFont(IMPACT_FONT);
                } else if (col == ARIAL_COL) {
                    c.setFont(ARIAL_BOLD_FONT);
                }
                return c;
            }
            @Override
            public Dimension getPreferredScrollableViewportSize() {
                return new Dimension(300, 125);
            }
        };
        table.setRowHeight(20);

        JTextField impactField = getFontEditorField(IMPACT_FONT);
        TableColumn impactColumn = table.getColumnModel().getColumn(IMPACT_COL);
        impactColumn.setCellEditor(new DefaultCellEditor(impactField));

        JTextField arialBoldField = getFontEditorField(ARIAL_BOLD_FONT);
        TableColumn arialColumn = table.getColumnModel().getColumn(ARIAL_COL);
        arialColumn.setCellEditor(new DefaultCellEditor(arialBoldField));

        return table;
    }

    public JTextField getFontEditorField(Font font) {
        JTextField field = new JTextField();
        field.setFont(font);
        return field;
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new ChangeFontInEditorDemo();
            }
        });
    }
}