在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

这是 实验性技术
检查 浏览器兼容性表格 要小心谨慎在生产中使用这之前。

FileSystemDirectoryEntry 接口方法 createReader () 返回 FileSystemDirectoryReader object which can be used to read the entries in the directory.

句法

directoryReader = FileSystemDirectoryEntry.createReader();
					

参数

None.

返回值

A FileSystemDirectoryReader object which can be used to read the directory's entries.

范例

This example creates a method called readDirectory() , which fetches all of the entries in the specified FileSystemDirectoryEntry and returns them in an array.

function readDirectory(directory) {
  let dirReader = directory.createReader();
  let entries = [];
  let getEntries = function() {
    dirReader.readEntries(function(results) {
      if (results.length) {
        entries = entries.concat(toArray(results));
        getEntries();
      }
    }, function(error) {
      /* handle error -- error is a FileError object */
    });
  };
  getEntries();
  return entries;
}
					

This works by creating an internal function, getEntries() , which calls itself recursively to get all the entries in the directory, concatenating each batch to the array. Each iteration, readEntries() is called to get more entries. When it returns an empty array, the end of the directory has beenr reached, and the recursion ends. Once control is returned to readDirectory() , the array is returned to the caller.

规范

规范	状态	注释
文件和目录条目 API The definition of 'createReader()' in that specification.	草案	最初的规范。

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
createReader	Chrome 13	Edge 79	Firefox 50	IE No	Opera No	Safari 11.1	WebView Android ≤37	Chrome Android 18	Firefox Android 50	Opera Android No	Safari iOS 11.3	Samsung Internet Android Yes

图例

完整支持

完整支持

不支持

不支持

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

另请参阅

• 文件和目录条目 API
• 文件系统 API 介绍
• FileSystemDirectoryReader
• FileSystemDirectoryEntry
• FileSystemFileEntry
• FileSystemEntry

元数据

• 最后修改： Dec 25, 2019

相关话题

1. 文件和目录条目 API
2. FileSystemDirectoryEntry
3. 方法

   1. createReader()
   2. getDirectory()
   3. getFile()
   4. removeRecursively()
4. 文件系统 API 相关页面

   1. FileError
   2. FileException
   3. FileHandle
   4. FileRequest
   5. FileSystem
   6. FileSystemDirectoryEntrySync
   7. FileSystemDirectoryReader
   8. FileSystemDirectoryReaderSync
   9. FileSystemEntry
   10. FileSystemEntrySync
   11. FileSystemFileEntry
   12. FileSystemFileEntrySync
   13. FileSystemFlags
   14. FileSystemSync
   15. HTMLInputElement
   16. LocalFileSystem
   17. LocalFileSystemSync
   18. LockedFile
   19. 元数据
   20. Window.requestFileSystem()
   21. Window.resolveLocalFileSystemURL()
   22. WorkerGlobalScope.requestFileSystemSync()