这就是您创建自己的方式的TreeCellRenderer
方式,它告诉您JTree
您想要的任何内容。由于您使用的是带有DefaultMutableTreeNode
节点的默认树模型,因此您必须提取其用户对象并根据该对象决定要绘制的内容。请注意,默认渲染器只是一个扩展的JLabel
,这就是为什么您可以在其中使用setIcon(...)
,setText(...)
等。
您的叶节点使用文件图标绘制的原因可能是默认渲染器根据DefaultMutableTreeNode.getAllowsChildren()
类似于我使用的方式选择图标Contact.isSomeProperty()
。
import java.awt.Component;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
public class Browser extends JFrame {
private JTree tree;
//ManagerOfContacts mngrOfContacts;
public Browser() {
//Generates the ManagerOfContacts and associated Contacts
//Driver driver = new Driver();
//mngrOfContacts = driver.getManagerOfContacts();
//---------------------------\\
DefaultMutableTreeNode contacts = new DefaultMutableTreeNode("Contacts");
createNodes(contacts);
tree = new JTree(contacts);
// use your own renderer (!)
tree.setCellRenderer(new MyTreeCellRenderer());
JScrollPane treeView = new JScrollPane(tree);
add(treeView);
setSize(400,400);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
}
public final void createNodes(DefaultMutableTreeNode top){
DefaultMutableTreeNode contactName;
// dummies
List<Contact> contacts = new ArrayList<Contact>();
contacts.add(new Contact("Me", true));
contacts.add(new Contact("You"));
Iterator<Contact> contactItr = contacts.iterator();
while(contactItr.hasNext()){
contactName = new DefaultMutableTreeNode(contactItr.next());
top.add(contactName);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
Browser browsr = new Browser();
}
});
}
// dummy
private static class Contact {
private boolean someProperty;
private String name;
public Contact(String name) {
this(name, false);
}
public Contact(String name, boolean property) {
this.someProperty = property;
this.name = name;
}
public boolean isSomeProperty() {
return someProperty;
}
public String getName() {
return name;
}
@Override
public String toString() {
return name;
}
}
// this is what you want
private static class MyTreeCellRenderer extends DefaultTreeCellRenderer {
@Override
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean hasFocus) {
super.getTreeCellRendererComponent(tree, value, sel, expanded, leaf, row, hasFocus);
// decide what icons you want by examining the node
if (value instanceof DefaultMutableTreeNode) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
if (node.getUserObject() instanceof String) {
// your root node, since you just put a String as a user obj
setIcon(UIManager.getIcon("FileView.computerIcon"));
} else if (node.getUserObject() instanceof Contact) {
// decide based on some property of your Contact obj
Contact contact = (Contact) node.getUserObject();
if (contact.isSomeProperty()) {
setIcon(UIManager.getIcon("FileView.hardDriveIcon"));
} else {
setIcon(UIManager.getIcon("FileChooser.homeFolderIcon"));
}
}
}
return this;
}
}
}
这应该让你开始。您应该在JTree 教程中阅读更多相关信息。