cFileEx Class

Advanced file operations class based on VB native Open statement, with good compatibility and interface consistent with cFileIO.

Description

cFileEx uses VB native Open statement for file operations, with the following characteristics compared to cFileIO:

• Better compatibility (does not depend on Win32 API)
• Additional data format support (Base64, Hex, Binary)
• Interface consistent with cFileIO, convenient for interchangeable use

Features:

• One instance can only operate on one file at a time
• Read content first enters internal buffer, then extracted via ReturnXXX methods
• Supports UTF-8, ANSI, UTF-16LE encodings
• Supports Base64, Hex, Binary string formats

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Properties

Property Name	Type	Description
IsOpen	Boolean	Whether file is open (read-only)
FilePath	String	Currently opened file path (read-only)
LastError	String	Last error message (read-only)
FileSize	Currency	File size (bytes)
BufferSize	Long	Current buffer byte count

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Methods

OpenFile

Opens a file, returns Me to support method chaining.

Syntax:

Public Function OpenFile(ByVal FilePath As String, Optional ByVal AccessMode As String = "RW") As cFileEx

Parameters:

Parameter	Type	Description
FilePath	String	File path to open
AccessMode	String	Optional. Access mode: R=read-only, W=write-only, RW=read-write (default)

Returns:

• Returns self instance, supports method chaining

Description:

• R mode: file must exist
• W mode: creates or overwrites file
• RW mode: creates file if it doesn't exist

Example:

Dim File As New cFileEx

' Open in read-only mode
File.OpenFile "C:\\data\\file.txt", "R"

' Open in read-write mode (method chaining)
Dim Content As String
Content = File.OpenFile("C:\\data\\file.txt", "RW").ReadData().ReturnText()

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CloseFile

Closes the currently opened file.

Syntax:

Public Sub CloseFile()

Example:

File.CloseFile

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ClearBuffer

Clears the internal buffer.

Syntax:

Public Function ClearBuffer() As cFileEx

Returns:

• Returns self instance, supports method chaining

Example:

File.ClearBuffer()

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SetBuffer

Fills the buffer with external byte array.

Syntax:

Public Function SetBuffer(Data() As Byte) As cFileEx

Parameters:

Parameter	Type	Description
Data	Byte()	Byte array to set

Returns:

• Returns self instance, supports method chaining

Example:

Dim Bytes() As Byte
Bytes = StrConv("Hello", vbFromUnicode)
File.SetBuffer Bytes

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AppendBuffer

Appends bytes to the buffer.

Syntax:

Public Function AppendBuffer(Data() As Byte) As cFileEx

Parameters:

Parameter	Type	Description
Data	Byte()	Byte array to append

Returns:

• Returns self instance, supports method chaining

Example:

Dim Part1() As Byte, Part2() As Byte
Part1 = StrConv("Hello ", vbFromUnicode)
Part2 = StrConv("World", vbFromUnicode)
File.SetBuffer(Part1).AppendBuffer(Part2)

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SetBufferText

Fills the buffer with string (default UTF-8 encoding).

Syntax:

Public Function SetBufferText(ByVal Text As String, Optional ByVal CharSet As String = "UTF-8") As cFileEx

Parameters:

Parameter	Type	Description
Text	String	Text to set
CharSet	String	Optional. Encoding: UTF-8(default), ANSI, UTF-16LE

Returns:

• Returns self instance, supports method chaining

Example:

File.SetBufferText "Hello World 你好世界"
File.SetBufferText "Hello World", "ANSI"

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SetBufferBase64

Fills the buffer with Base64 string.

Syntax:

Public Function SetBufferBase64(ByVal Base64String As String) As cFileEx

Parameters:

Parameter	Type	Description
Base64String	String	Base64-encoded string

Returns:

• Returns self instance, supports method chaining

Example:

Dim Base64 As String
Base64 = "SGVsbG8gV29ybGQ="
File.SetBufferBase64 Base64

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SetBufferHex

Fills the buffer with Hex string.

Syntax:

Public Function SetBufferHex(ByVal HexString As String, Optional ByVal Separator As String = " ") As cFileEx

Parameters:

Parameter	Type	Description
HexString	String	Hex-encoded string
Separator	String	Optional. Separator, default is space

Returns:

• Returns self instance, supports method chaining

Description:

• Automatically removes separators and whitespace
• Supports spaces, tabs, newlines as separators

Example:

' Space separated
File.SetBufferHex "48 65 6C 6C 6F"

' Without separator
File.SetBufferHex "48656C6C6F", ""

' Custom separator
File.SetBufferHex "48-65-6C-6C-6F", "-"

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SetBufferBinString

Fills the buffer with binary string.

Syntax:

Public Function SetBufferBinString(ByVal BinString As String, Optional ByVal Separator As String = " ") As cFileEx

Parameters:

Parameter	Type	Description
BinString	String	Binary string (e.g., "01001000")
Separator	String	Optional. Separator, default is space

Returns:

• Returns self instance, supports method chaining

Description:

• Each group of 8 bits represents one byte
• Pads with leading zeros if length is not a multiple of 8

Example:

' Space separated
File.SetBufferBinString "01001000 01100101 01101100 01101100 01101111"

' Without separator
File.SetBufferBinString "0100100001100101", ""

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ReadData

Reads specified range of file into internal buffer.

Syntax:

Public Function ReadData(Optional ByVal StartPos As Long = -1, Optional ByVal EndPos As Long = -1) As cFileEx

Parameters:

Parameter	Type	Description
StartPos	Long	Optional. Start position (1-based, -1 means from beginning)
EndPos	Long	Optional. End position (1-based, -1 means to end)

Returns:

• Returns self instance, supports method chaining

Description:

• Position parameters are 1-based byte positions (different from cFileIO)

Example:

' Read entire file
File.OpenFile("C:\\data\\file.txt", "R").ReadData()

' Read bytes 1-1000
File.ReadData(1, 1000)

' Read from byte 1001 to end
File.ReadData(1001, -1)

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ReturnText

Returns text from buffer.

Syntax:

Public Function ReturnText(Optional ByVal CharSet As String = "UTF-8") As String

Parameters:

Parameter	Type	Description
CharSet	String	Optional. Encoding: UTF-8(default), ANSI, UTF-16LE

Returns:

• String content

Example:

Dim Content As String
Content = File.OpenFile("C:\\data\\file.txt", "R") _
              .ReadData() _
              .ReturnText("UTF-8")

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ReturnBytes

Returns byte array from buffer (copy).

Syntax:

Public Function ReturnBytes() As Byte()

Returns:

• Byte array

Example:

Dim Bytes() As Byte
Bytes = File.ReadData().ReturnBytes()

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ReturnBase64

Returns Base64-encoded string from buffer.

Syntax:

Public Function ReturnBase64() As String

Returns:

• Base64-encoded string

Example:

Dim Base64 As String
Base64 = File.OpenFile("C:\\data\\image.png", "R").ReadData().ReturnBase64()

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ReturnHex

Returns Hex-encoded string from buffer.

Syntax:

Public Function ReturnHex(Optional ByVal Separator As String = " ") As String

Parameters:

Parameter	Type	Description
Separator	String	Optional. Separator, default is space

Returns:

• Hex-encoded string

Example:

Dim HexStr As String
HexStr = File.ReadData().ReturnHex(" ")
' Output: 48 65 6C 6C 6F

HexStr = File.ReadData().ReturnHex("")
' Output: 48656C6C6F

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ReturnBinString

Returns binary string from buffer.

Syntax:

Public Function ReturnBinString(Optional ByVal Separator As String = " ") As String

Parameters:

Parameter	Type	Description
Separator	String	Optional. Separator, default is space

Returns:

• Binary string (8 bits per group)

Example:

Dim BinStr As String
BinStr = File.ReadData().ReturnBinString(" ")
' Output: 01001000 01100101 01101100 01101100 01101111

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SaveData

Writes internal buffer to file.

Syntax:

Public Function SaveData(Optional ByVal FilePath As String, Optional ByVal IsAppend As Boolean = False) As cFileEx

Parameters:

Parameter	Type	Description
FilePath	String	Optional. Target path, uses path from OpenFile if not provided
IsAppend	Boolean	Optional. False=overwrite (default), True=append to end of file

Returns:

• Returns self instance, supports method chaining

Example:

' Overwrite
File.SetBufferText("Hello").SaveData("C:\\data\\output.txt")

' Append
File.SetBufferText("\nNew line").SaveData("C:\\data\\log.txt", True)

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Usage Examples

Example 1: Basic File Read/Write

Sub BasicFileExample()
    Dim File As New cFileEx
    
    ' Write file
    File.SetBufferText("Hello World 你好世界", "UTF-8") _
        .SaveData("C:\\data\\test.txt")
    
    ' Read file
    Dim Content As String
    Content = File.OpenFile("C:\\data\\test.txt", "R") _
                  .ReadData() _
                  .ReturnText("UTF-8")
    
    Debug.Print Content
    File.CloseFile
End Sub

Example 2: Hex Data Processing

Sub HexDataExample()
    Dim File As New cFileEx
    
    ' Create data from Hex string
    File.SetBufferHex("48 65 6C 6C 6F 20 57 6F 72 6C 64")
    
    ' Return in different formats
    Debug.Print "Text: " & File.ReturnText()           ' Hello World
    Debug.Print "Base64: " & File.ReturnBase64()       ' SGVsbG8gV29ybGQ=
    Debug.Print "Hex(no sep): " & File.ReturnHex("")   ' 48656C6C6F20576F726C64
    Debug.Print "Binary: " & File.ReturnBinString(" ") ' 01001000 01100101 ...
End Sub

Example 3: Binary Data Processing

Sub BinaryDataExample()
    Dim File As New cFileEx
    
    ' Create data from binary string
    File.SetBufferBinString "01000001 01000010 01000011"  ' ABC
    
    ' Save as file
    File.SaveData "C:\\data\\binary.bin"
    
    ' Read and display as Hex
    File.OpenFile("C:\\data\\binary.bin", "R").ReadData()
    Debug.Print File.ReturnHex()  ' 41 42 43
End Sub

Example 4: Base64 Encoding/Decoding

Sub Base64Example()
    Dim File As New cFileEx
    
    ' Read file and convert to Base64
    File.OpenFile("C:\\data\\image.png", "R").ReadData()
    Dim Base64 As String
    Base64 = File.ReturnBase64()
    
    ' Restore from Base64
    File.SetBufferBase64(Base64).SaveData "C:\\data\\image_copy.png"
    
    Debug.Print "Base64 encoding/decoding completed"
End Sub

Example 5: Data Format Conversion

Sub FormatConversionExample()
    Dim File As New cFileEx
    
    ' Original text
    Dim Text As String
    Text = "Hello"
    
    ' Text -> Hex
    File.SetBufferText(Text)
    Debug.Print "Hex: " & File.ReturnHex(" ")      ' 48 65 6C 6C 6F
    
    ' Hex -> Text
    File.SetBufferHex("48 65 6C 6C 6F")
    Debug.Print "Text: " & File.ReturnText()       ' Hello
    
    ' Text -> Base64
    File.SetBufferText(Text)
    Debug.Print "Base64: " & File.ReturnBase64()   ' SGVsbG8=
    
    ' Base64 -> Text
    File.SetBufferBase64("SGVsbG8=")
    Debug.Print "Text: " & File.ReturnText()       ' Hello
End Sub

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cFileIO vs cFileEx Comparison

Feature	cFileIO	cFileEx
Implementation	Win32 API	VB Open statement
Large file support	Yes (>2GB)	No (VB limitation)
Compatibility	Requires Windows	Better cross-platform compatibility
Base64 support	Yes	Yes
Hex support	No	Yes
Binary support	No	Yes
Read position	0-based	1-based

Selection Guide:

• Need to handle large files (>2GB) → Use cFileIO
• Need Hex/Binary format support → Use cFileEx
• General file operations → Either works