VB6: how combine ARGB color elements?

[cambalinho]

i have tried several ways, but i always get an overflow error :(
how can i combine the ARGB color elements?

Public Function ARGB(ByVal alpha As Byte, ByVal red As Byte, ByVal green As Byte, ByVal blue As Byte) As Long


    Dim color As Variant

    color = CDec(alpha) * 256 ' Alpha
    color = (color * 256) + CDec(red) ' Red
    color = (color * 256) + CDec(green) ' Green
    color = CDec((color * 256) + CDec(blue)) ' Blue 

    ARGB = CDec(color) 'overflow error
End Function

[rproffitt]

Nod to https://learn.microsoft.com/en-us/office/vba/language/reference/user-interface-help/variant-data-type
Why use Variant here?
Seems Integer would work but since you might exceed 32768 go with long integers.

PS. Added with edit. Be sure all the constants and variables in your math are long as well. 256 isn't long.

[cambalinho]

i was avoiding the overflow.... but the problem is much more than the data type... and it's only on Alpha element... but finally seems fixed:

Public Function ARGB(ByVal alpha As Byte, ByVal red As Byte, ByVal green As Byte, ByVal blue As Byte) As Long
    '1st testing the Alpha element:
    ARGB = (alpha And &H7F) * &H1000000 Or -((alpha And &H80) <> 0) * &H80000000 _
        Or red * &H10000 _
        Or green * &H100& _
        Or blue
End Function

thank you so much for all