Convert argb to string - winforms

Question

Which method allows convert ARGB to string as 'int, int, int'? Example. The $Main background color is set as a string '0, 100, 200'. Return $Main.BackColor gives ARGB but not string '0, 100, 200':
$Main = [System.Windows.Forms.Form] #{
BackColor = '0, 100, 200'
}
$Main.BackColor
--------------
R : 0
G : 100
B : 200
A : 255
IsKnownColor : False
IsEmpty : False
IsNamedColor : False
IsSystemColor : False
Name : ff0064c8
The To.String() method returns the result Color [A=255, R=0, G=100, B=200]
. This is not what is expected.
At the moment I am doing this:
('R', 'G', 'B').ForEach({ $Main.BackColor.$_ }) -join ', '
--------------
0, 100, 200
However, I hope that there are special methods for converting as ARGB to string, as string to ARGB. What are these methods? Thanks

Answer 1

However, I hope that there are special methods for converting as argb to string, as string to argb. What are these methods?
You'd think so, but to my knowledge there isn't a builtin two-way convertion for this, unfortunately.
Here are a couple of things you can do instead:
Create your own ConvertFrom-Color function:
function ConvertFrom-Color
{
param(
[Parameter(Mandatory=$true,ValueFromPipeline=$true)]
[System.Drawing.Color[]]$InputColor
)
process {
foreach($color in $InputColor){
$color.R,$color.G,$color.B -join ', '
}
}
}
And use when needed:
PS C:\> $colorString = $Main.BackColor |ConvertFrom-Color
PS C:\> $colorString
0, 100, 200
Use an [int]
An ARGB color consists of 4 1-byte channels, which fits perfectly into a 32-bit integer. If you need to communicate a distinct color using a single argument, this is already supported:
PS C:\> $color = [System.Drawing.Color]'0,100,100'
PS C:\> $color.ToArgb()
-16751516
PS C:\> $argbValue = $color.ToArgb()
PS C:\> [System.Drawing.Color]::FromArgb($argbValue)
R : 0
G : 100
B : 100
A : 255
IsKnownColor : False
IsEmpty : False
IsNamedColor : False
IsSystemColor : False
Name : ff006464
Just like with your initial string representation, it's worth highlighting that converting from the [int] representation works both with explicit casts and implicit conversions when assigning to typed properties:
$argbValue = -16751516
# This works just fine
[System.Drawing.Color]$argbValue
# As does this
[System.Windows.Forms.Form]#{ BackColor = $argbValue }
Override Color.ToString()
Since you're interested in changing the behavior of the default string representation of System.Drawing.Color, you might as well override the ToString() method implementation:
Update-TypeData -TypeName System.Drawing.Color -MemberType ScriptMethod -MemberName ToString -Value {
$this.psobject.Properties['R','G','B'].Value -join ', '
} -Force
Now all instances of [System.Drawing.Color] will use your custom ToString() method when converted to a string:
PS C:\> "$($Main.BackColor)"
0, 100, 200

Answer 2

There are some nice and initiative answers for this question, but it looks like all have overlooked the correct way, using type converters. There is a ColorConverter responsible for ConvertTo and ConvertFrom String/Color:
$Color = [System.Drawing.Color]'0, 100, 200'
[System.Drawing.ColorConverter]::new().ConvertToString($Color)
# Result: 0, 100, 200
This is the same class which is used by PropertyGrid to convert the string to Color or Color and vice versa.
It will take care of A element of the color as well, for example if you create the color like 100, 0, 100, 200. This solution automatically include or ignore A portion whenever is required:
$Color = [System.Drawing.Color]'100, 0, 100, 200'
[System.Drawing.ColorConverter]::new().ConvertToString($Color)
# Result: 100, 0, 100, 200

Answer 3

Reza Aghaei's helpful answer shows the proper solution and Mathias R. Jessen's excellent answer shows robust alternatives.
Let me complement them with a pragmatic hack; while deriving serializable representations from for-display strings (.ToString()) is generally ill-advised, the format at hand is unlikely to change in a way that will break this:
PS> $Main.BackColor -replace '[^\d,]' # remove all chars. except digits and commas
255,0,100,200
Note: The above includes the alpha value, unlike the original input string; however, casting back to [System.Drawing.Color] works equally well.

Answer 4

As far as I know there is no custom string format in System.Drawing.Color. You need custom conversion. You can use your method or any other. I would use custom expression and string interpolation:
$c = [System.Drawing.Color]'0, 100, 200'
#simulate array
$c,$c | select #{N="Color";E={"$($_.R), $($_.G), $($_.B)"}}
Result:
Color
-----
0, 100, 200
0, 100, 200