Java 遍历由DefaultMutableTreeNode生成的树
我们使用Java中指定的Java 遍历由DefaultMutableTreeNode生成的树,java,swing,parsing,tree,Java,Swing,Parsing,Tree,我们使用Java中指定的DefaultMutableTreeNode实现了一个树结构 有没有办法穿越它,那是内在的 如果没有,请建议其他技术。如果您想遍历树,可以调用breadthFirstEnumeration()或depthFirstEnumeration(),以遍历树中的所有节点 例如: DefaultMutableTreeNode root = ... Enumeration en = root.depthFirstEnumeration(); while (en.hasMoreEle
DefaultMutableTreeNode
实现了一个树结构
有没有办法穿越它,那是内在的
如果没有,请建议其他技术。如果您想遍历树,可以调用
breadthFirstEnumeration()
或depthFirstEnumeration()
,以遍历树中的所有节点
例如:
DefaultMutableTreeNode root = ...
Enumeration en = root.depthFirstEnumeration();
while (en.hasMoreElements()) {
// Unfortunately the enumeration isn't genericised so we need to downcast
// when calling nextElement():
DefaultMutableTreeNode node = (DefaultMutableTreeNode) en.nextElement();
}
正确,面包优先是有序的。也支持预排序(先是根,然后是子项)(预排序计数)理论上,从节点遍历树有四种方法(
DefaultMutableTreeNode
):
broadthfirstumeration
depthFirstEnumeration
preorderEnumeration
postorderEnumeration
JavaDoc对这些方法的区别有点简洁。我来这里寻找答案,但最后我自己做了测试,代码如下:
TreeModel model = tree.getModel();
DefaultMutableTreeNode rootNode = (DefaultMutableTreeNode) model.getRoot();
// Just changing enumeration kind here
Enumeration<DefaultMutableTreeNode> en = rootNode.preorderEnumeration();
while (en.hasMoreElements())
{
DefaultMutableTreeNode node = en.nextElement();
TreeNode[] path = node.getPath();
System.out.println((node.isLeaf() ? " - " : "+ ") + path[path.length - 1]);
}
♦ 预订单:如上所示♦ 深度优先/邮购:
叶F1,叶F1,文件夹1
叶SF1,叶SF1,子文件夹1
叶SF2,叶SF2,子文件夹2,文件夹2,根
♦ 呼吸优先:
根
文件夹1,文件夹2
叶F1,叶F1,子文件夹1,子文件夹2
叶SF 1、叶SF 1、叶SF 2、叶SF 2这是对3种枚举方法的另一种描述,可能更容易理解
en = root.breadthFirstEnumeration();
//Enumeration lists all nodes at depth 0 (aka root)
//Then all nodes at depth 1 (aka root's children, top to bottom ordering)
//Then all nodes at depth 2, and so on till max depth reached
en = root.preorderEnumeration();
//Imagine your JTree is fully expanded (where each node = a row)
//Enumeration will list nodes from top to bottom (regardless of leaf or not)
en = root.postorderEnumeration(); //Equivalent to root.depthFirstEnumeration();
//Imagine a fully expanded copy of your JTree (where each node = a row)
//This will allow you to visualize what Enumeration List will look like
while(treecopy.hasNodes() ) {
list 1st leaf sighted going from top to bottom, then remove that leaf }
//as the leafs are removed, branches then become leafs, and root is last enumerated.
你解析它是什么意思?通常,您会解析表达式以构建内部表示(如已有的树结构)。你只是想遍历树吗?很抱歉。是的,我的意思是遍历树。如何访问搜索算法返回的每个节点?你能给我指一个好的资源吗?最后是我需要的!我使用了一个ArrayList,在创建节点时添加了节点,这很好,但是因为我在不同的文件夹中使用了重复的条目,所以我需要为每个文件夹创建一个新的数组,然后它会很快变大。也感谢下面的答案,我可以处理他们的2倍快!起初我没有说出我的意思,我是想把它作为一个可视化辅助工具,但我无意中说出了它的字面意思。我现在已经改了,希望它更清晰,谢谢你的反馈。
en = root.breadthFirstEnumeration();
//Enumeration lists all nodes at depth 0 (aka root)
//Then all nodes at depth 1 (aka root's children, top to bottom ordering)
//Then all nodes at depth 2, and so on till max depth reached
en = root.preorderEnumeration();
//Imagine your JTree is fully expanded (where each node = a row)
//Enumeration will list nodes from top to bottom (regardless of leaf or not)
en = root.postorderEnumeration(); //Equivalent to root.depthFirstEnumeration();
//Imagine a fully expanded copy of your JTree (where each node = a row)
//This will allow you to visualize what Enumeration List will look like
while(treecopy.hasNodes() ) {
list 1st leaf sighted going from top to bottom, then remove that leaf }
//as the leafs are removed, branches then become leafs, and root is last enumerated.