高分求助,ADODC控件向MDB数据库写入图片的一段代码看不懂,请求指教!!

[vbcool]

以下程序代码取自<<王国荣 VB6.0 数据库程序设计>>第86页
希望高手能指点,做详细分解,谢谢!!

Declare Sub RtlMoveMemory lib "KERNEL32" (LpvDest As Any, lpvSource As Any, ByVal cbCopy As Long)

'这个API 函数在VB API Text Viewer 中查不到,它的作用是什么?

Sub SavePictureToAdodc (rs As ADODB.Recordset, ByVal FileName As String)

Dim Length As Long, f As Integer
Length=FileLen(FileName)

ReDim bArray(Length+12) as Byte, bArray2(Length) As Byte
'为什么bArray要多加12
bArray(0)=&H6C
bArray(1)=&H74
'以上两句有何作用?
RtlMoveMemory bArray(4), Length, 4
'以上一句又有何用?
f=FreeFile
Open FileName For Binary As #f
Get #f, , bArray2
Close #1

RtlMoveMemory bArray(8) , bArray2(0) , Length
rs("相片").AppendChunk bArray
'以上这两句又有何作用?

End Sub