How to set icon in a column of JTable?

问题:

I am able to set the column's header but not able to set icon in all the rows of first column of JTable.

public class iconRenderer extends DefaultTableCellRenderer{
    public Component getTableCellRendererComponent(JTable table,Object obj,boolean isSelected,boolean hasFocus,int row,int column){
        imageicon i=(imageicon)obj;
        if(obj==i)
            setIcon(i.imageIcon);
        setBorder(UIManager.getBorder("TableHeader.cellBorder"));
        setHorizontalAlignment(JLabel.CENTER);
        return this;
    }
}

public class imageicon{
    ImageIcon imageIcon;
    imageicon(ImageIcon icon){
        imageIcon=icon;
    }
}  

---

and below lines in my BuildTable() method.

    public void SetIcon(JTable table, int col_index, ImageIcon icon){
      table.getTableHeader().getColumnModel().getColumn(col_index).setHeaderRenderer(new iconRenderer());
      table.getColumnModel().getColumn(col_index).setHeaderValue(new imageicon(icon));
}

---

How can we set it for all rows of first columns? I have tried with for loop but didnt get yet for rows to iterate to set icon. Or is there any other way?

回答1:

There is no need to create a custom render. JTable already supports an Icon renderer. YOu just need to tell the table to use this renderer. This is done by overriding the getColumnClass(...) method of the table model:

import java.awt.*;
import javax.swing.*;
import javax.swing.table.*;

public class TableIcon extends JPanel
{
    public TableIcon()
    {
        Icon aboutIcon = new ImageIcon("about16.gif");
        Icon addIcon = new ImageIcon("add16.gif");
        Icon copyIcon = new ImageIcon("copy16.gif");

        String[] columnNames = {"Picture", "Description"};
        Object[][] data =
        {
            {aboutIcon, "About"},
            {addIcon, "Add"},
            {copyIcon, "Copy"},
        };

        DefaultTableModel model = new DefaultTableModel(data, columnNames)
        {
            //  Returning the Class of each column will allow different
            //  renderers to be used based on Class
            public Class getColumnClass(int column)
            {
                return getValueAt(0, column).getClass();
            }
        };
        JTable table = new JTable( model );
        table.setPreferredScrollableViewportSize(table.getPreferredSize());

        JScrollPane scrollPane = new JScrollPane( table );
        add( scrollPane );
    }

    private static void createAndShowGUI()
    {
        JFrame frame = new JFrame("Table Icon");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new TableIcon());
        frame.setLocationByPlatform( true );
        frame.pack();
        frame.setVisible( true );
    }

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

}

回答2:

You are just using iconRenderer for the render of your header. Also set the Column's Cell Reneder to be an instance of iconRenderer as well. Call setCellRenderer on the column.

http://download.oracle.com/javase/6/docs/api/javax/swing/table/TableColumn.html#setCellRenderer(javax.swing.table.TableCellRenderer)

Side note: Java coding standards specify that class names should start with capital letters, so iconRenderer should be IconRenderer instead.