在此页

• 特性
• 方法
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

TreeWalker 对象表示文档子树节点及其位置。

A TreeWalker 可以创建使用 Document.createTreeWalker() 方法。

特性

此接口未继承任何特性。

TreeWalker.root 只读

返回 节点 representing the root node as specified when the TreeWalker was created.

TreeWalker.whatToShow 只读

返回 unsigned long being a bitmask made of constants describing the types of 节点 that must be presented. Non-matching nodes are skipped, but their children may be included, if relevant. The possible values are:

常量	数值	描述
NodeFilter.SHOW_ALL	-1 (that is the max value of unsigned long )	展示所有节点。
NodeFilter.SHOW_ATTRIBUTE	2	Shows attribute Attr nodes. This is meaningful only when creating a TreeWalker 采用 Attr node as its root. In this case, it means that the attribute node will appear in the first position of the iteration or traversal. Since attributes are never children of other nodes, they do not appear when traversing over the document tree.
NodeFilter.SHOW_CDATA_SECTION	8	展示 CDATASection 节点。
NodeFilter.SHOW_COMMENT	128	展示 注释 节点。
NodeFilter.SHOW_DOCUMENT	256	展示 Document 节点。
NodeFilter.SHOW_DOCUMENT_FRAGMENT	1024	展示 DocumentFragment 节点。
NodeFilter.SHOW_DOCUMENT_TYPE	512	展示 DocumentType 节点。
NodeFilter.SHOW_ELEMENT	1	展示 元素 节点。
NodeFilter.SHOW_ENTITY	32	展示 Entity nodes. This is meaningful only when creating a TreeWalker 采用 Entity node as its root; in this case, it means that the Entity node will appear in the first position of the traversal. Since entities are not part of the document tree, they do not appear when traversing over the document tree.
NodeFilter.SHOW_ENTITY_REFERENCE	16	展示 EntityReference 节点。
NodeFilter.SHOW_NOTATION	2048	展示 Notation nodes. This is meaningful only when creating a TreeWalker 采用 Notation node as its root; in this case, it means that the Notation node will appear in the first position of the traversal. Since entities are not part of the document tree, they do not appear when traversing over the document tree.
NodeFilter.SHOW_PROCESSING_INSTRUCTION	64	展示 ProcessingInstruction 节点。
NodeFilter.SHOW_TEXT	4	展示 文本 节点。

TreeWalker.filter 只读

返回 NodeFilter 用于选择相关节点。

TreeWalker.expandEntityReferences 只读

是 布尔 indicating, when discarding an EntityReference its whole sub-tree must be discarded at the same time.

TreeWalker.currentNode

Is the 节点 on which the TreeWalker is currently pointing at.

方法

This interface doesn't inherit any method.

注意 : in the context of a TreeWalker , a node is visible if it exists in the logical view determined by the whatToShow and filter parameter arguments. (Whether or not the node is visible on the screen is irrelevant.)

TreeWalker.parentNode()

Moves the current 节点 to the first visible ancestor node in the document order, and returns the found node. It also moves the current node to this one. If no such node exists, or if it is before that the root node defined at the object construction, returns null and the current node is not changed.

TreeWalker.firstChild()

Moves the current 节点 to the first visible child of the current node, and returns the found child. It also moves the current node to this child. If no such child exists, returns null and the current node is not changed.

TreeWalker.lastChild()

Moves the current 节点 to the last visible child of the current node, and returns the found child. It also moves the current node to this child. If no such child exists, null is returned and the current node is not changed.

TreeWalker.previousSibling()

Moves the current 节点 to its previous sibling, if any, and returns the found sibling. If there is no such node, return null and the current node is not changed.

TreeWalker.nextSibling()

Moves the current 节点 to its next sibling, if any, and returns the found sibling. If there is no such node, null is returned and the current node is not changed.

TreeWalker.previousNode()

Moves the current 节点 to the previous visible node in the document order, and returns the found node. It also moves the current node to this one. If no such node exists, or if it is before that the root node defined at the object construction, returns null and the current node is not changed.

TreeWalker.nextNode()

Moves the current 节点 to the next visible node in the document order, and returns the found node. It also moves the current node to this one. If no such node exists, returns null and the current node is not changed.

规范

规范	状态	注释
DOM The definition of 'TreeWalker' in that specification.	实时标准	移除 expandEntityReferences 特性。
Document Object Model (DOM) Level 2 Traversal and Range Specification The definition of 'TreeWalker' in that specification.	过时	初始定义。

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
TreeWalker	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
currentNode	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
expandEntityReferences 弃用	Chrome 1	Edge 12	Firefox 4 — 21	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4 — 21	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
filter	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
firstChild	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
lastChild	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
nextNode	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
nextSibling	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
parentNode	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
previousNode	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
previousSibling	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
root	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes
whatToShow	Chrome 1	Edge 12	Firefox 4	IE 9	Opera 9	Safari 3	WebView Android 3	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3	Samsung Internet Android Yes

图例

完整支持

完整支持

不支持

不支持

弃用。不要用于新网站。

弃用。不要用于新网站。

另请参阅

• 创建者方法： Document.createTreeWalker() .
• 相关接口： NodeFilter , NodeIterator .

元数据

• 最后修改： Mar 17, 2020

相关话题

1. DOM (文档对象模型)
2. TreeWalker
3. 特性

   1. currentNode
   2. expandEntityReferences
   3. filter
   4. root
   5. whatToShow
4. 方法

   1. firstChild()
   2. lastChild()
   3. nextNode()
   4. nextSibling()
   5. parentNode()
   6. previousNode()
   7. previousSibling()
5. DOM 相关页面

   1. AbortController
   2. AbortSignal
   3. AbstractRange
   4. Attr
   5. ByteString
   6. CDATASection
   7. CSSPrimitiveValue
   8. CSSValue
   9. CSSValueList
   10. CharacterData
   11. ChildNode
   12. 注释
   13. CustomEvent
   14. DOMConfiguration
   15. DOMError
   16. DOMErrorHandler
   17. DOMException
   18. DOMImplementation
   19. DOMImplementationList
   20. DOMImplementationRegistry
   21. DOMImplementationSource
   22. DOMLocator
   23. DOMObject
   24. DOMParser
   25. DOMPoint
   26. DOMPointInit
   27. DOMPointReadOnly
   28. DOMRect
   29. DOMString
   30. DOMTimeStamp
   31. DOMTokenList
   32. DOMUserData
   33. Document
   34. DocumentFragment
   35. DocumentType
   36. 元素
   37. ElementTraversal
   38. Entity
   39. EntityReference
   40. 事件
   41. EventTarget
   42. HTMLCollection
   43. MutationObserver
   44. 节点
   45. NodeFilter
   46. NodeIterator
   47. NodeList
   48. NonDocumentTypeChildNode
   49. ProcessingInstruction
   50. PromiseResolver
   51. 范围
   52. StaticRange
   53. 文本
   54. TextDecoder
   55. TextEncoder
   56. TimeRanges
   57. TypeInfo
   58. USVString
   59. UserDataHandler
   60. XMLDocument