如何在JTree里根据状态来在节点前显示不同的图片

Question

以前我回答过这类问题，你搜一下吧

Answer 1

搜不到 :(好像以前的旧帖都没有了

Answer 2

原来这样简单
import javax.swing.tree.TreeCellRenderer;
import javax.swing.plaf.ColorUIResource;
import javax.swing.plaf.FontUIResource;
import java.awt.*;
import java.io.File;
import javax.swing.*;
import javax.swing.tree.DefaultTreeCellRenderer;public class MyTreeCellRenderer
    extends JPanel
    implements TreeCellRenderer {  /** 用于显示节点文字。*/
  private DefaultTreeCellRenderer defaultTreeCellRenderer;  /** 用于显示自定义图标。*/
  private JLabel m_ShowStatusLabel;  /** 统一图标来源的路径用。*/
  private MyIconFile m_File;  /**用于显示节点前的图片。*/
  private Icon m_StatusIcon;  /**构造器。*/
  public MyTreeCellRenderer() {
    this.m_File = new MyIconFile();
    this.m_ShowStatusLabel = new JLabel();    this.m_StatusIcon = m_File.getAllSelIcon();
    this.m_ShowStatusLabel.setIcon(this.m_StatusIcon);
    this.add(this.m_ShowStatusLabel, null);    this.defaultTreeCellRenderer = new DefaultTreeCellRenderer();
    this.add(this.defaultTreeCellRenderer, null);
  }/**调default的，显示文字*/
  public Component getTreeCellRendererComponent(JTree tree, Object value,
                                                boolean sel,
                                                boolean expanded,
                                                boolean leaf, int row,
                                                boolean hasFocus) {
    this.defaultTreeCellRenderer.getTreeCellRendererComponent(tree, value, sel,
        expanded, leaf, row, hasFocus);    setComponentOrientation(tree.getComponentOrientation());
    return this;
  }/** 在super.paint(g)前自己加状态判断，然后调m_showSatusLabel.setIcon(icon)*/
  public void paint(Graphics g) {
    int labelWidth = this.defaultTreeCellRenderer.getWidth();
    int labelHeight = this.defaultTreeCellRenderer.getHeight();
    this.defaultTreeCellRenderer.setBounds(new Rectangle(16, 0, labelWidth,
        labelHeight));
    this.m_ShowStatusLabel.setBounds(new Rectangle(0, 0, 16, 16));    super.paint(g);
  }
}
/***************************************************************/
class MyIconFile {
  private static String dirPath;
  private static String allSelIconFileName = "AllSel.gif";
  private static String someSelIconFileName = "SomeSel.gif";
  private static String noneSelIconFileName = "NoneSel.gif";  static {
    dirPath = new File("").getAbsolutePath() + "/";
    while (dirPath.indexOf(File.separator) != -1) {
      int index = dirPath.indexOf(File.separator);
      dirPath = dirPath.substring(0, index) + "/" +
          dirPath.substring(index + 1, dirPath.length());
    }
  }  public static Icon getAllSelIcon() {
    return new ImageIcon(dirPath + allSelIconFileName);
  }
}