Java Swing JTable 设置隔行变色

Posted 2020-07-28 swbzmx

设置JTable隔行变色，关键是重写方法prepareRenderer.

——————————–以下是演示代码，可自己运行看看——————————-

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Rectangle;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.WindowConstants;
import javax.swing.plaf.nimbus.NimbusLookAndFeel;
import javax.swing.table.TableCellRenderer;

public class JTableAlternateRowColors {

    public JTableAlternateRowColors() {
        initComponents();
    }

    public static void main(String[] args) {

        try {
            UIManager.setLookAndFeel(new NimbusLookAndFeel());
        } catch (UnsupportedLookAndFeelException e) {
            e.printStackTrace();
        }

        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new JTableAlternateRowColors();
            }
        });
    }

    private void initComponents() {

        final JFrame jFrame = new JFrame("Nimbus alternate row coloring");

        MyTable table = new MyTable(new String[][]{
                    {"one", "two", "three"},
                    {"one", "two", "three"},
                    {"one", "two", "three"}
                }, new String[]{"col1", "col2", "col3"});

        table.setFillsViewportHeight(true);//will fill the empty spaces too if any

        table.setPreferredScrollableViewportSize(table.getPreferredSize());

        JScrollPane jScrollPane = new JScrollPane(table);

        jFrame.getContentPane().add(jScrollPane);
        jFrame.pack();
        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        jFrame.setVisible(true);
    }
}

class MyTable extends JTable {

    public MyTable(String[][] data, String[] fields) {
        super(data, fields);
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        if (getFillsViewportHeight()) {
            paintEmptyRows(g);
        }
    }

    /**
     * Paints the backgrounds of the implied empty rows when the table model is
     * insufficient to fill all the visible area available to us. We don‘t
     * involve cell renderers, because we have no data.
     */
    protected void paintEmptyRows(Graphics g) {
        final int rowCount = getRowCount();
        final Rectangle clip = g.getClipBounds();
        if (rowCount * rowHeight < clip.height) {
            for (int i = rowCount; i <= clip.height / rowHeight; ++i) {
                g.setColor(colorForRow(i));
                g.fillRect(clip.x, i * rowHeight, clip.width, rowHeight);
            }
        }
    }

    /**
     * Returns the appropriate background color for the given row.
     */
    protected Color colorForRow(int row) {
        return (row % 2 == 0) ? Color.RED : Color.PINK;
    }

    /**
     * Shades alternate rows in different colors.
     */
    @Override
    public Component prepareRenderer(TableCellRenderer renderer, int row, int column) {
        Component c = super.prepareRenderer(renderer, row, column);
        if (isCellSelected(row, column) == false) {
            c.setBackground(colorForRow(row));
            c.setForeground(UIManager.getColor("Table.foreground"));
        } else {
            c.setBackground(UIManager.getColor("Table.selectionBackground"));
            c.setForeground(UIManager.getColor("Table.selectionForeground"));
        }
        return c;
    }
}