# FileSystemManager.readFile(Object object)

with Promise style call: Not supported

Mini Program plugin: Support, need to Mini Program base library version no less than 2.19.2

Read local file content

# parameter

# Object object

attribute	type	Required	Introductions	Minimum version
filePath	string	yes	Path to the file to read (Local path)
encoding	string	no	Specifies the character encoding for the read file, if the Encoding, the ArrayBuffer Format to read the binary contents of a file
position	number	no	Start reading from the specified location in the file or from the file header if not specified. Read range should be left closed and right open range [position, position+length)。有效范围：[0, fileLength - 1]. Unit: byte	2.10.0
length	number	no	Specifies the length of the file, if not specified, read to the end of the document. Scope of validity:[1, fileLength]. Unit: byte	2.10.0
success	function	no	Interface calls the successful callback function
fail	function	no	Interface calls failed callback functions
complete	function	no	Callback function at the end of an interface call (both successful and unsuccessful calls are executed)

object.encoding Legal value

value	Introductions	Minimum version
ascii
base64
binary
hex
ucs2	Read in small endorder
ucs-2	Read in small endorder
Utf16le	Read in small endorder
utf-16le	Read in small endorder
utf-8
utf8
latin1

# object.success callback

# parameter

# Object res

attribute	type	Introductions
data	string/ArrayBuffer	Document content

# object.fail callback

# parameter

# Object res

attribute	type	Introductions
errMsg	string	Error message

res.errMsg Legal value

value	Introductions	Minimum version
fail No such file or directory, open ${filePath}	Specified filePath Directory does not exist
fail permission denied, open ${dirPath}	Specified filePath Path not read
fail sdcard not mounted	Android sdcard Mount failure

# sample code

const fs = wx.getFileSystemManager()
fs.readFile({
  filePath: `${wx.env.USER_DATA_PATH}/hello.txt`, 
  encoding: 'utf8',
  position: 0,
  success(res) {
    console.log(res.data)
  },
  fail(res) {
    console.error(res)
  }
})

// Synchronous interface
try {
  const res = fs.readFileSync(`${wx.env.USER_DATA_PATH}/hello.txt`,  'utf8', 0)
  console.log(res)
} catch(e) {
  console.error(e)
}