Passing a color value into a procedure

[DaveBo]

Pardon my stupidity.
How can I specify a color as an optional arg in a sub with a default, and then pass in a value?

e.g. I tried this and it failed miserably
Optional ByVal RayColor As Color = System.Drawing.Color.White

Color complains
"Optional parameters cannot have structure types"

System.Drawing.Color.White complains
"Constant expression is required"

Thanks, (a very confused) DaveBo

[Cander]

You are going to have to use the actual values for the colors and turn the optional args into string or seperate rgb values, depending on how you do it. Like it says, optional paramaters cannot use structures. Color is a struct.

[DaveBo]

Thanks,
I thought System.Drawing.Color.White equated to a color constant value - for white, e.g. like in VB6
? vbWhite
returns 16777215

In the .Net Command window I tried
? System.Drawing.Color.White
and it returned

{System.Drawing.Color}
    A: 255
    AliceBlue: {System.Drawing.Color}
	:
    MintCream: {System.Drawing.Color}
    < More... (The first 100 of 151 items were displayed.) >.

I never knew "white" could be so complicated.

[pax]

Hi.

Instead of "Optional" you could use overloaded subs.

Private Sub A()
        A(Color.White)
    End Sub
    Private Sub A(ByVal C As Color)
        'Do your stuff
    End Sub

If you call A with a color the second sub will be called.
If you call A without a color the first sub will be called, which in turn just calls the second one with your default color.

Does this help?

[DaveBo]

But it does work!

Thanks Pax

[pax]

Your welcome.

Actually, that's the way MS does it.
All functions that has several combinations of parameters are made like that.