如何将图像插入 JTable 单元格

Question

有人可以指出如何将图像添加到 Java 表格单元格中的正确方向吗？

Answer 1

我创建了自己的实现 TableCellRenderer 的类。我可以从 JLabel 扩展这个类，但我更喜欢保持它独立并使用 JLabel 'label' 作为类组件。

public class GLabel implements TableCellRenderer{
    //The JLabel that is used to display image
    private final JLabel label = new JLabel();  
    
    /**
     * 
     * @param text
     * @param image 
     */
    public GLabel(String text, ImageIcon image) {
        label.setText(text);
        label.setIcon(image);
    }
    
    public GLabel(){}

    public JLabel getLabel() {
        return label;
    }      

    /**
     *
     * @param table the JTable that is asking the renderer to draw; can be null
     * @param value the value of the cell to be rendered. 
     * It is up to the specific renderer to interpret and draw the value. 
     * For example, if value is the string "true", it could be rendered as a string or it could be rendered as a check box that is checked. 
     * null is a valid value
     * @param isSelected true if the cell is to be rendered with the selection highlighted; otherwise false
     * @param hasFocus if true, render cell appropriately. For example, put a special border on the cell, if the cell can be edited, render in the color used to indicate editing
     * @param row the row index of the cell being drawn. When drawing the header, the value of row is -1
     * @param column the column index of the cell being drawn
     * @return 
     */
    @Override
    public Component getTableCellRendererComponent(JTable table,
                                      Object value,
                                      boolean isSelected,
                                      boolean hasFocus,
                                      int row,
                                      int column) {
        GLabel gLabel = (GLabel)value;
        return (Component) gLabel.getLabel();
    }
}

我创建了一个新的 DefaultTableModel 对象。我重写了 getColumnClass() 方法以在运行时传递适当的类。

private final DefaultTableModel tblmodel = new DefaultTableModel() {        
        /**
         * This method is called by table cell renderer.
         * The method returns class of the cell data. This helps the renderer to display icons and 
         * other graphics in the table.
         */
        @Override
        public Class getColumnClass(int column)
        {
            for(int i = 0; i < tblmodel.getRowCount(); i++)
            {
                //The first valid value of a cell of given column is retrieved.
                if(getValueAt(i,column) != null)
                {
                    return getValueAt(i, column).getClass();
                }
            }
            //if no valid value is found, default renderer is returned.
            return super.getColumnClass(column);
        }
        
    };

我使用我创建的 DefaultTableModel 创建了 JTable 对象。

JTable jtable = new JTable(tblmodel);

我为 GLabel 类设置了默认渲染器

jtable.setDefaultRenderer(GLabel.class, new GLabel());

我创建了新的 GLabel 对象。

GLabel glabel = new GLabel("testing", new ImageIcon("c://imagepath"));

最后，我使用 TableModel 的 addRow(Object[] rowData) 方法将 GLabel 添加到 JTable 中。

Answer 2

1- 为 jtable 添加标签（为此创建类）

 class LabelRendar implements TableCellRenderer{

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
      //  throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
        return (Component)value;
    }

}

2- 代码 jButton 添加图片

DefaultTableModel m = (DefaultTableModel) jTable1.getModel();
      jTable1.getColumn("image").setCellRenderer(new LabelRendar());  // call class 
      JLabel lebl=new JLabel("hello");
      lebl.setIcon(new javax.swing.ImageIcon(getClass().getResource("/main/bslogo120.png"))); // NOI18N
          m.addRow(new Object[]{"", "","",lebl});

Answer 3

JTable 已经为图标提供了默认渲染器。您只需要告诉表在给定列中存储了哪些数据，以便它可以选择适当的渲染器。这是通过覆盖 getColumnClass(...) 方法来完成的：

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();
            }
        });
    }

}

Answer 4

要么在前面创建图像图标：

ImageIcon icon = new ImageIcon("image.gif");
table.setValueAt(icon, row, column);

或者您可以尝试覆盖图标字段的渲染器：

static class IconRenderer extends DefaultTableCellRenderer {
  public IconRenderer() { super(); }

  public void setValue(Object value) {
    if (value == null) {
      setText("");
    }
    else
    {
      setIcon(value);
    }
}