How can you convert an integer into a VB.NET color?

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Guest

In VB6, foreground and background colors of controls had to be assigned a
single number. If you knew the RGB values for the color, you still had to
convert them into the single number accepatable to the VB6 controls.

In VB.NET, you can't set colors that way anymore, now you have to use a
"color". There is a way to convert RGB values to a "color", using the
Color.FromARGB method. But there doens't seem to be a way to convert the old
single numbers into a "color".

In VB6, there was a method to convert rgb values into a single number, using
the RGB method. This method is still available in VB6 through the
Microsoft.VisualBasic.Information namespace. However, I have the single
numbers I used before (that were REQUIRED in VB6), I don't have separate Red,
Green, and Blue values for those numbers. Neither VB6 nor VB.NET seem to have
a method for converting a single number back to its component red, green, and
blue values!! (If there IS one, please someone tell me what it is!)

So, if there is no way to convert the single numbers back to rgb values OR
to convert them to the new "color" values, then VB.NET has changed the whole
system for assigning colors to controls, and is giving me no way to convert
the numbers that were required before into the new system. That's not very
nice!

If anyone has an answer for this, please let me know.
 
Hello Bob,

Check out the System.Drawing.ColorTranslator class. (hint: VB6 color storage
is defined by OLE).

-Boo
 
Hello Bob,

Check out the System.Drawing.ColorTranslator class. (hint: VB6 color storage
is defined by OLE).

-Boo
Click to expand...

There's even a discussion in the Help file about VB6/VB2005 color
handling changes. What a novel idea.

Gene
 
In VB6, foreground and background colors of controls had to be
assigned a single number. If you knew the RGB values for the color,
you still had to convert them into the single number accepatable to
the VB6 controls.

In VB.NET, you can't set colors that way anymore, now you have to use
a "color". There is a way to convert RGB values to a "color", using
the Color.FromARGB method. But there doens't seem to be a way to
convert the old single numbers into a "color".

In VB6, there was a method to convert rgb values into a single number,
using the RGB method. This method is still available in VB6 through
the Microsoft.VisualBasic.Information namespace. However, I have the
single numbers I used before (that were REQUIRED in VB6), I don't have
separate Red, Green, and Blue values for those numbers. Neither VB6
nor VB.NET seem to have a method for converting a single number back
to its component red, green, and blue values!! (If there IS one,
please someone tell me what it is!)

So, if there is no way to convert the single numbers back to rgb
values OR to convert them to the new "color" values, then VB.NET has
changed the whole system for assigning colors to controls, and is
giving me no way to convert the numbers that were required before into
the new system. That's not very nice!

If anyone has an answer for this, please let me know.
Click to expand...

Color.FromARGB(integer)

It is overloaded. See the msdn help for color.fromArgb.

to get the R, G and B from a color just use

dim r as byte = myColor.R
etc.

Colors are just int32s. ARGB = byte order.
So you can split with bitwise operators:

here's some general messing about:

Dim c As Color = Color.Chocolate
Debug.WriteLine(Hex(c.ToArgb))
' outputs: FFD2691E
Dim red As Byte = c.R
Dim green As Byte = c.G
Dim blue As Byte = c.B
Dim c2 As Color = Color.FromArgb(&HFFD2691E)
Debug.WriteLine(Hex(c2.ToArgb))
' outputs: FFD2691E
Dim red2 As Byte = &HD2
Dim green2 As Byte = &H69
Dim blue2 As Byte = &H1E
Dim c3 As Color = Color.FromArgb(red2, green2, blue2)
Debug.WriteLine(Hex(c3.ToArgb))
' outputs: FFD2691E
' do it manually:
Dim color4int As Integer = &HFFD2691E
Dim R4 As Byte = (color4int >> 16) And &HFF
Dim G4 As Byte = (color4int >> 8) And &HFF
Dim b4 As Byte = (color4int And &HFF)
Debug.WriteLine(String.Concat("red: ", Hex(R4), ", green : ", Hex(G4), ",
blue: ", Hex(b4)))
' outputs: red: D2, green : 69, blue: 1E
' reassemble:
Dim color5int As Integer = (CInt(R4) << 16) Or (CInt(G4) << 8) Or b4
Dim color5 As Color = Color.FromArgb(color5int)
Debug.WriteLine(Hex(color5.ToArgb))
' outputs D2691E - no alpha!
' use another override to supply the alpha for a base color:
Dim color6 As Color = Color.FromArgb(&HFF, Color.FromArgb(color5int))
Debug.WriteLine(Hex(color6.ToArgb))
' outputs FFD2691E
' or you could have added it bitwise:
Dim color7int As Integer = (&HFF << 24) Or (CInt(R4) << 16) Or (CInt(G4)
<< 8) Or b4
Dim color7 As Color = Color.FromArgb(color7int)
Debug.WriteLine(Hex(color6.ToArgb))


Always check the overload list for a method. It pops up in intellisense:

after typing this:
dim c as color = color.fromARGB(

intellisense pops up
"1 of 4 FromARGB(argb as integer) as System.Drawing.Color
argb = A value specifying the 32 bit color value"

and you can press the up and down arrows to see the other overloads.

For more info on an overload, look in the help...
 
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