怎么在Java中使用JTree树状组件？相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。
一、简单样式
TreeNodeDemo.java
package awtDemo;
import javax.swing.JFrame;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
public class TreeNodeDemo {
public static void main(String[] args) {
// 创建没有父节点和子节点、但允许有子节点的树节点，并使用指定的用户对象对它进行初始化。
// public DefaultMutableTreeNode(Object userObject)
DefaultMutableTreeNode group1 = new DefaultMutableTreeNode("软件部");
TreeNode node1 = new TreeNode();
node1.setName("王雨");
node1.setNickName("漫天飞舞");
group1.add(new DefaultMutableTreeNode(node1));
TreeNode node2 = new TreeNode();
node2.setName("陈梦");
node2.setNickName("梦");
group1.add(new DefaultMutableTreeNode(node2));
TreeNode node3 = new TreeNode();
node3.setName("上官飞儿");
node3.setNickName("飞儿");
group1.add(new DefaultMutableTreeNode(node3));
DefaultMutableTreeNode group2 = new DefaultMutableTreeNode("销售部");
TreeNode node4 = new TreeNode();
node4.setName("上官婉儿");
node4.setNickName("婉儿");
group2.add(new DefaultMutableTreeNode(node4));
TreeNode node5 = new TreeNode();
node5.setName("上官巧儿");
node5.setNickName("巧儿");
group2.add(new DefaultMutableTreeNode(node5));
DefaultMutableTreeNode top = new DefaultMutableTreeNode("职员管理");
top.add(group1);
top.add(group2);
final JTree tree = new JTree(top);
JFrame f = new JFrame("JTreeDemo - www.jb51.net");
f.add(tree);
f.setSize(300, 300);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// 添加选择事件
tree.addTreeSelectionListener(new TreeSelectionListener()
{
@Override
public void valueChanged(TreeSelectionEvent e)
{
DefaultMutableTreeNode node = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
if (node == null){
return;
}//if
Object object = node.getUserObject();
TreeNode user = (TreeNode) object;
System.out.println("你选择了：" + user.toString());
}
});
}
}TreeNode.java
package awtDemo;
public class TreeNode {
private String nickName = "";
private String name = "";
private String phone = "";
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getNickName() {
return nickName;
}
public void setNickName(String nickName) {
this.nickName = nickName;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
// 重点在toString，节点的显示文本就是toString
public String toString()
{
return name + "["+nickName+"]";
}
}二、图标样式
运行效果：
TreeNode.java
package awtDemo;
public class TreeNode {
private String nickName = "";
private String name = "";
private String phone = "";
private int age;
private String imagePath = "";
public String getImagePath() {
return imagePath;
}
public void setImagePath(String imagePath) {
this.imagePath = imagePath;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getNickName() {
return nickName;
}
public void setNickName(String nickName) {
this.nickName = nickName;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
// 重点在toString，节点的显示文本就是toString
public String toString()
{
return name + "["+nickName+"]";
}
}TreeCellRenderer.java
package awtDemo;
import java.awt.Component;
import javax.swing.ImageIcon;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
/**
* 自定义树描述类,将树的每个节点设置成不同的图标
*
*/
public class TreeCellRenderer extends DefaultTreeCellRenderer{
private static final long serialVersionUID = 1L;
/**
* 重写父类DefaultTreeCellRenderer的方法
*/
@Override
public Component getTreeCellRendererComponent(JTree tree, Object value,
boolean selected, boolean expanded, boolean isLeaf, int row,boolean hasFocus)
{
// 选中
if (selected)
{
setForeground(getTextSelectionColor());
}
else
{
setForeground(getTextNonSelectionColor());
}
// TreeNode
DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode) value;
Object obj = treeNode.getUserObject();
if (obj instanceof TreeNode)
{
TreeNode node = (TreeNode) obj;
DefaultTreeCellRenderer tempCellRenderer = new DefaultTreeCellRenderer();
tempCellRenderer.setLeafIcon(new ImageIcon(node.getImagePath()));
return tempCellRenderer.getTreeCellRendererComponent(tree, node.toString(), selected, expanded, true, row, hasFocus);
}
else if (obj instanceof String)
{
String text = (String) obj;
DefaultTreeCellRenderer tempCellRenderer = new DefaultTreeCellRenderer();
tempCellRenderer.setOpenIcon(new ImageIcon("Image/open.jpg"));
tempCellRenderer.setClosedIcon(new ImageIcon("Image/close.jpg"));
return tempCellRenderer.getTreeCellRendererComponent(tree, text, selected, expanded, false, row, hasFocus);
}
return super.getTreeCellRendererComponent(tree, value, selected, expanded, isLeaf, row, hasFocus);
}
}TreeNodeDemo.java
package awtDemo;
import javax.swing.JFrame;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
public class TreeNodeDemo {
public static void main(String[] args) {
// 创建没有父节点和子节点、但允许有子节点的树节点，并使用指定的用户对象对它进行初始化。
// public DefaultMutableTreeNode(Object userObject)
DefaultMutableTreeNode group1 = new DefaultMutableTreeNode("软件部");
TreeNode node1 = new TreeNode();
node1.setName("王雨");
node1.setNickName("漫天飞舞");
node1.setImagePath("Image/1.jpg");
group1.add(new DefaultMutableTreeNode(node1));
TreeNode node2 = new TreeNode();
node2.setName("陈梦");
node2.setNickName("梦");
node2.setImagePath("Image/2.jpg");
group1.add(new DefaultMutableTreeNode(node2));
TreeNode node3 = new TreeNode();
node3.setName("上官飞儿");
node3.setNickName("飞儿");
node3.setImagePath("Image/3.jpg");
group1.add(new DefaultMutableTreeNode(node3));
DefaultMutableTreeNode group2 = new DefaultMutableTreeNode("销售部");
TreeNode node4 = new TreeNode();
node4.setName("上官婉儿");
node4.setNickName("婉儿");
node4.setImagePath("Image/4.jpg");
group2.add(new DefaultMutableTreeNode(node4));
TreeNode node5 = new TreeNode();
node5.setName("上官巧儿");
node5.setNickName("巧儿");
node5.setImagePath("Image/5.jpg");
group2.add(new DefaultMutableTreeNode(node5));
DefaultMutableTreeNode root = new DefaultMutableTreeNode();
root.add(group1);
root.add(group2);
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
final JTree tree = new JTree(root);
tree.setCellRenderer(new TreeCellRenderer());
tree.putClientProperty("JTree.lineStyle", "None");
tree.setRootVisible(true);
JFrame frame = new JFrame("JTreeDemo - www.jb51.net");
frame.add(tree);
frame.setSize(300, 300);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// 添加选择事件
tree.addTreeSelectionListener(new TreeSelectionListener()
{
@Override
public void valueChanged(TreeSelectionEvent e)
{
DefaultMutableTreeNode node = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
if (node == null){
return;
}//if
Object object = node.getUserObject();
if(object instanceof TreeNode)
{
TreeNode user = (TreeNode) object;
System.out.println("你点击了：" + user.toString());
}
else if(object instanceof String)
{
String text = (String)object;
System.out.println("你点击了：" + text);
}
}
});
}
}看完上述内容，你们掌握怎么在Java中使用JTree树状组件的方法了吗？如果还想学到更多技能或想了解更多相关内容，欢迎关注亿速云行业资讯频道，感谢各位的阅读！
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