java - setCellRenderer() 不起作用

Question

我正在尝试为特定列设置渲染器，但不知何故，该渲染器并未用于渲染该列。有什么解释吗？

tabledata = new LendDataTable();
table.setModel(tabledata);
TableColumn xx = table.getColumnModel().getColumn(3);
xx.setCellRenderer(new BookBackRenderer());//here it doesn't (there are 7 rows in total)
table.setDefaultRenderer(Integer.class, new BookBackRenderer());// here it works
add(table, BorderLayout.CENTER);



public  class BookBackRenderer extends DefaultTableCellRenderer {

/**
 * 
 */
private static final long serialVersionUID = 1L;

public BookBackRenderer() {
    // TODO Auto-generated constructor stub

}

@Override
public Component getTableCellRendererComponent(JTable table, Object value,
        boolean isSelected, boolean hasFocus, int row, int column) {


    System.out.println(column);
    return super.getTableCellRendererComponent(table, value.toString() + "xy", isSelected, hasFocus, row, column);
}

}

问题似乎与 TableModel 有关。一旦我使用 DefaultTableModel，它就可以完美工作。我的表模型的代码:

/**
 * 
 */
package client.gui;

import java.awt.Component;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.EventObject;
import java.util.LinkedList;
import java.util.List;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.event.CellEditorListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableCellEditor;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableModel;
import javax.swing.text.DateFormatter;

import org.json.JSONArray;

import lbvs.Leiheintrag;

/**
 * @author John
 *
 */
public class LendDataTable extends AbstractTableModel  implements
TableModel{
    private List<Leiheintrag> lendlist;

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    /**
     * 
     */
    public LendDataTable() {
        // TODO Auto-generated constructor stub
        lendlist = new LinkedList<Leiheintrag> ();
    }
    public void setData (List<Leiheintrag> list)
    {
        lendlist = list;
        this.fireTableStructureChanged();
        this.fireTableDataChanged();



    }

    /* (non-Javadoc)
     * @see javax.swing.table.TableModel#getRowCount()
     */
    @Override
    public int getRowCount() {
        // TODO Auto-generated method stub
        return lendlist.size();
    }

    /* (non-Javadoc)
     * @see javax.swing.table.TableModel#getColumnCount()
     */
    @Override
    public int getColumnCount() {
        // TODO Auto-generated method stub
        return 7;
    }

    /* (non-Javadoc)
     * @see javax.swing.table.TableModel#getValueAt(int, int)
     */
    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        // TODO Auto-generated method stub
        Leiheintrag eintr = lendlist.get(rowIndex);
        switch (columnIndex){
        case 0:
            return eintr.getBuch();
        case 1:
            return eintr.getLeihdatum();
        case 2:
            return eintr.getAbgabe_bis();
        case 3:
            return ((Long)eintr.getRueck_datum());
        case 4:
            return eintr.getBezahlt_am();
        case 5:
            return eintr.getKosten();
        case 6 :
            return eintr.getLast_edit_user();
         default:
            return null;


        }
    }
    public Class<?> getColumnClass(int columnIndex){
        switch (columnIndex){
        case 0:
            return Integer.class;
        case 1:
            return Long.class;
        case 2:
            return Long.class;
        case 3:
            return Long.class;
        case 4:
            return Long.class;
        case 5:
            return Float.class;
        case 6 :
            return Integer.class;
         default:
            return null;


        }
    }
}

感谢您的帮助

Answer 1

the problem seems to be realted to the TableModel. Once I use a DefaultTableModel it works perfect

下面的方法似乎是问题所在。

public void setData (List<Leiheintrag> list)
{
    lendlist = list;
    this.fireTableStructureChanged();
    this.fireTableDataChanged();
}

当您调用 fireTableStructureChange() 时，JTable 将重新创建 TableColumnModel(以及所有 TableColumn)，这意味着您的渲染器将不再与 TableColumn 3 关联。

我认为您可以只使用 fireTableDataChanged()，或者如果这不起作用，则使用 fireTableRowsInserted()。

如果您愿意，可以查看 DefaultTableModel 的源代码，了解 setDataVector() 方法调用的内容，因为两个模型的概念相同.