jtree用法及jtree使用经验总结 -凯发k8网页登录

在实际开发过程中会经常使用jtree组件，平时会遇到这样或那样的问题，在此将偶得一点经验写下来，与大家共享，希望对大家有所帮助。

private jtree jtnetdevice;//数组件申明
private jscrollpane jsptree;//滚动面板申明

1、初始化
    defaultmutabletreenode rootnode = new defaultmutabletreenode("root");
    jtnetdevice = new jtree(rootnode);
    jtnetdevice.setautoscrolls(true);
    gettreeselectionmodel().setselectionmode(treeselectionmodel.single_tree_selection);//设置单选模式
    jsptree = new jscrollpane();
    jsptree.getviewport().add(jtnetdevice, null);

2、三个经常使用的取值函数
  private defaulttreemodel gettreemodel(){
    return (defaulttreemodel)jtnetdevice.getmodel();
  }

  private defaultmutabletreenode getrootnode(){
    return (defaultmutabletreenode)gettreemodel().getroot();
  }
 
  private treeselectionmodel gettreeselectionmodel(){
    return jtnetdevice.getselectionmodel();
  }
 

3、根据node得到path：
  treepath visiblepath = new treepath(gettreemodel().getpathtoroot(node));

4、根据path展开到该节点
  jtnetdevice.makevisible(visiblepath);

5、根据path设定该节点选定
  jtnetdevice.setselectionpath(visiblepath);

6、选中节点的方法
  首先，根据节点得到树路径，其中chosen为需要选中的节点
  treepath visiblepath = new treepath( ( (defaulttreemodel) jtnetdevice.getmodel()).
                                        getpathtoroot(chosen));
  然后根据path选中该节点
  jtnetdevice.setselectionpath(visiblepath);

7、滚动到可见位置
  jtnetdevice.scrollpathtovisible(visiblepath);

8、给jtree添加右键弹出菜单
  void jtnetdevice_mousereleased(mouseevent e) {
    if (e.ispopuptrigger()) {
      jpopupmenu1.show(e.getcomponent(), e.getx(), e.gety());//弹出右键菜单
    }
  }

9、关于jtree的展开
   // if expand is true, expands all nodes in the tree.
   // otherwise, collapses all nodes in the tree.
   public void expandall(jtree tree, boolean expand) {
       treenode root = (treenode)tree.getmodel().getroot();
  
       // traverse tree from root
       expandall(tree, new treepath(root), expand);
   }
   private void expandall(jtree tree, treepath parent, boolean expand) {
       // traverse children
       treenode node = (treenode)parent.getlastpathcomponent();
       if (node.getchildcount() >= 0) {
           for (enumeration e=node.children(); e.hasmoreelements(); ) {
               treenode n = (treenode)e.nextelement();
               treepath path = parent.pathbyaddingchild(n);
               expandall(tree, path, expand);
           }
       }
  
       // expansion or collapse must be done bottom-up
       if (expand) {
           tree.expandpath(parent);
       } else {
           tree.collapsepath(parent);
       }
   }
 

10、如何遍历jtree
   // 创建树
   jtree tree = new jtree();
  
   // 添加树节点......
  
   // 遍历所有节点
   visitallnodes(tree);
  
   // 仅遍历展开的节点
   visitallexpandednodes(tree);
  
   // traverse all nodes in tree
   public void visitallnodes(jtree tree) {
       treenode root = (treenode)tree.getmodel().getroot();
       visitallnodes(root);
   }
   public void visitallnodes(treenode node) {
       // node is visited exactly once
       process(node);
  
       if (node.getchildcount() >= 0) {
           for (enumeration e=node.children(); e.hasmoreelements(); ) {
               treenode n = (treenode)e.nextelement();
               visitallnodes(n);
           }
       }
   }
  
   // traverse all expanded nodes in tree
   public void visitallexpandednodes(jtree tree) {
       treenode root = (treenode)tree.getmodel().getroot();
       visitallexpandednodes(tree, new treepath(root));
   }
   public void visitallexpandednodes(jtree tree, treepath parent) {
       // return if node is not expanded
       if (!tree.isvisible(parent)) {
           return;
       }
  
       // node is visible and is visited exactly once
       treenode node = (treenode)parent.getlastpathcomponent();
       process(node);
  
       // visit all children
       if (node.getchildcount() >= 0) {
           for (enumeration e=node.children(); e.hasmoreelements(); ) {
               treenode n = (treenode)e.nextelement();
               treepath path = parent.pathbyaddingchild(n);
               visitallexpandednodes(tree, path);
           }
       }
   }