[RESOLVED] Can't pass byte array as parameter in VB6

This might be a super basic issue, but I am a super basic programmer, so here I go.

I am creating a byte array with image information extacted from a database field (with a routine RhinoBull posted here some time ago)

These are the steps:

1. Create Recordset with all records in table which contain an image in the IMAGE field
2. Loop through the Recordset, and extract data in the IMAGE field to a byte() variable
3. With that info (per record) call a procedure that will use that byte() variable

Code:

---

Public Sub ExtractImage()

Dim bytes() As Byte

Dim file_length As Long
Dim num_blocks As Long
Dim left_over As Long
Dim block_num As Long
Dim hgt As Single
Dim Opr As New TablasManager
Dim Str_SQl As String
Dim Str_Cn_Prod As String
Str_Cn_Prod = "driver={SQL Server};server=200.9.220.58;database=SIG;uid=sa;pwd="
Str_SQl = "EXEC SIG.dbo.BT_L_Choferes"

On Error GoTo ErrHandler
   
    Screen.MousePointer = vbHourglass
   
    Set rs = Opr.EjecutarSPconRS(Str_SQl, adOpenForwardOnly, adLockReadOnly)
   
    If rs.EOF Then
        Screen.MousePointer = vbDefault
        Exit Sub
    End If
   
    If IsNull(rs.Fields("BioID")) Then
        Screen.MousePointer = vbDefault
        Exit Sub
    End If
   
    rs.MoveFirst
    Do While Not rs.EOF
   
        file_length = rs.Fields("Filesize")
       
        num_blocks = file_length / BLOCK_SIZE
        left_over = file_length Mod BLOCK_SIZE
       
        'get all chunks and write then to a temp file
        For block_num = 1 To num_blocks
            bytes() = rs.Fields("BioID").GetChunk(BLOCK_SIZE)
            'Put #file_num, , bytes()
        Next block_num
        If left_over > 0 Then
            bytes() = rs.Fields("BioID").GetChunk(left_over)
            'Put #file_num, , bytes()
        End If
 
        cmdEnrollFinger2 (bytes())

    Loop
   
   
    Screen.MousePointer = vbDefault
    Exit Sub

ErrHandler:

    Debug.Print Err.Description
    Err.Clear
    Screen.MousePointer = vbDefault
   
    'Resume Next
    Exit Sub

End Sub



Private Sub cmdEnrollFinger2(ByRef huella() As Byte)
    Dim iStatus As Long
    Dim iEnSize As Long
    Dim r_value, r_value2 As Boolean
                                   
        r_value2 = bAPI4_HMFVEnroll(SENSOR_RESOLUTION, SENSOR_WIDTH, SENSOR_HEIGHT, huella(0), pEnrolledFeatures(0), iEnSize, iStatus)

                                           
End Sub

---

When I call cmdEnrollFinger2 (bytes()) from the first procedure I get an error (in spanish) that says something like "Compile error: Type mismatch error: an array or a user defined type was expected"

I kind of remember that passing byte arrays as parameters was a bit tricky, but I can't find any specific information on the web

Anyone can help??

Thanks

To start with you should not put brackets outside the parameters, because you are not using the Call keyword (or returning the value of a function). It should be like this:

Code:

---

        cmdEnrollFinger2 bytes()

---

That is likely to solve the issue, but if not try also removing the remaining brackets.

Thanks! That solved it...

Good stuff. :)

To explain a little, you can put brackets around any value you like (eg: a = 1 + 2 can be re-written as a = (1) + (2) ), which is effectively what you had... but when you do that VB automatically changes the data type sometimes, and that can cause problems.


As you now have it sorted out, could you please do us a little favour, and mark the thread as Resolved?
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