Vb.net how do i receive a new instance of an extension method without a previous instance?

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I don't know how exactly to put this in words, Using a color as an example:

I know how to write basic <Extension()> methods:

VB

<Extension()>
Public Function GetRedValue(byval c as Color) as byte
    Return c.R
End Function

I could use:

VB

Dim Col as Color = Color.LimeGreen
Label1.Text = Col.GetRedValue().ToString

And it would return the value of Color.R as expected.

What I am trying to figure out is how to run a method without having an instance of color already created in order to return a new instance of that object.

It seems like the Color structure can inherently do it. When you create a new color you can use a predefined color or define the object like:

VB

Dim col as Color = Color.FromARGB(Alpha, Red, Green, Blue)

without having an instance already created.

How to I create my own method that work in the same fashion
Example:

VB

<Extension()>
Public Function FromHSV(byval c as Color, Hue as Single, Saturation as Single, Value as Single) as Color
    Dim ReturnColor as Color = ConvertToRGB(Hue, Saturation, Value) '<<== My Own Routine to return a color
Return ReturnColor
End Function

So that I may use it like:

VB

Dim Col as Color = Color.FromHSV(0.5, 0.2, 1.0)

or even

VB

Dim Col as Color = Color.MyCustomColor

I'm hoping I am making myself clear as I was not sure of the correct terminology for what I am trying to accomplish.
Any help is appreciated, Thank You!

What I have tried:

I thought the Shared parameter would work, but you can't use Shared within a module and you can't use <Extension()> within a class.

I have searched and found nothing that helps.

Posted 3-Mar-16 21:37pm

FatzBomb

Updated 3-Mar-16 23:41pm

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Richard Deeming · Accepted Answer · 2016-03-03T23:41:00

Extension Methods (Visual Basic)[^]:
Extension methods make it possible to write a method that can be called as if it were an instance method of the existing type.

Extension methods can only be used as instance methods on the type. You're trying to define a new Shared method on the type, which isn't possible.

Instead, you'll need to use your module name to call your function:

VB.NET

Public Module ColorExtensions
    Public Function FromHSV(ByVal hue As Single, ByVal saturation As Single, ByVal value As Single) As Color
        ...
    End Function
End Module
...
Dim col As Color = ColorExtensions.FromHSV(0.5, 0.2, 1.0)