在此页

• 最佳实践
• Attribute
• 错误代码
• 浏览器兼容性
• 另请参阅
• 相关话题

过时
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

Represents an error that occurs while using the FileReader 接口。

注意： This interface is obsolete per the latest specification. Use the new DOM4 DOMError interface instead.

在 文件系统 API ， FileError represents error conditions that you might encounter while accessing the file system using the asynchronous API. It extends the FileError interface described in File Writer and adds several new error codes.

FileError objects are passed to error callbacks. The objects have a code that shows the type of error that occurred.

最佳实践

Most people don't read the page on errors and exceptions unless they're stumped. So the following are a few tips that could help you avoid some pitfalls.

Error callbacks are not optional for your sanity

Although error callbacks are optional, you should include them in the arguments of the methods for the sake of the sanity of your users. A web app could fail for various reasons, so you don't want to spend the rest of your day guessing what's going on and going through maddening troubleshooting.

Don't run your app from file://

For security reasons, browsers do not allow you to run your app from file:// . In fact, many of the powerful storage APIs (such as File System, BlobBuilder, and FileReader) throw errors if you run the app locally from file:// . When you're just testing your app, and you don't want to set up a web server, you can bypass the security restriction on Chrome. Just start Chrome with the --allow-file-access-from-files flag. Use the flag only for testing purposes.

属性

属性	类型	描述
code	unsigned short	The most appropriate error code for the condition. See 错误代码 对于可能的值。

错误代码

注意： Do not rely on the numeric values of the constants, which might change as the specifications continue to change. Use the constant names instead.

常量	值	描述
ENCODING_ERR	5	The URL is malformed. Make sure that the URL is complete and valid.
INVALID_MODIFICATION_ERR	9	The modification requested is not allowed. For example, the app might be trying to move a directory into its own child or moving a file into its parent directory without changing its name.
INVALID_STATE_ERR	7	The operation cannot be performed on the current state of the interface object. For example, the state that was cached in an interface object has changed since it was last read from disk.
NO_MODIFICATION_ALLOWED_ERR	6	The state of the underlying file system prevents any writing to a file or a directory.
NOT_FOUND_ERR	1	A required file or directory could not be found at the time an operation was processed. For example, a file did not exist but was being opened.
NOT_READABLE_ERR	4	The file or directory cannot be read, typically due to permission problems that occur after a reference to a file has been acquired (for example, the file or directory is concurrently locked by another application).
PATH_EXISTS_ERR	12	The file or directory with the same path already exists.
QUOTA_EXCEEDED_ERR	10	Either there's not enough remaining storage space or the storage quota was reached and the user declined to give more space to the database. To ask for more storage, see Managing HTML5 Offline Storage .
SECURITY_ERR	2	Access to the files were denied for one of the following reasons: The files might be unsafe for access within a Web application. Too many calls are being made on file resources. Other unspecified security error code or situations.
TYPE_MISMATCH_ERR	11	The app looked up an entry, but the entry found is of the wrong type. For example, the app is asking for a directory, when the entry is really a file.

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
FileError 弃用 非标	Chrome 13 — 53 Prefixed 不支持 13 — 53 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge ?	Firefox ? — 13 不支持 ? — 13 FileError interface has been removed starting with Firefox 13.0. Instead the more general DOMError interface is used and returned by FileReader.error .	IE No	Opera ? — 40	Safari No	WebView Android ? — 53 Prefixed 不支持 ? — 53 Prefixed Prefixed Implemented with the vendor prefix: webkit	Chrome Android 18 — 53 Prefixed 不支持 18 — 53 Prefixed Prefixed Implemented with the vendor prefix: webkit	Firefox Android ? — 14 不支持 ? — 14 FileError interface has been removed starting with Firefox 13.0. Instead the more general DOMError interface is used and returned by FileReader.error .	Opera Android ? — 41	Safari iOS No	Samsung Internet Android 1.0 — 6.0 Prefixed 不支持 1.0 — 6.0 Prefixed Prefixed Implemented with the vendor prefix: webkit

图例

不支持

不支持

兼容性未知 ?

兼容性未知

非标。预期跨浏览器支持较差。

非标。预期跨浏览器支持较差。

弃用。不要用于新网站。

弃用。不要用于新网站。

见实现注意事项。

要求使用供应商前缀或不同名称。

要求使用供应商前缀或不同名称。

另请参阅

• Basic Concepts About the File System API
• FileReader
• File
• Blob
• Specification: FileAPI Errors and exceptions WD

元数据

• 最后修改： 2019 年 3 月 23 日

相关话题

1. 文件和目录条目 API
2. FileError
3. 文件系统 API 相关页面

   1. FileException
   2. FileHandle
   3. FileRequest
   4. FileSystem
   5. FileSystemDirectoryEntry
   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()