convert Uint32 to System.drawing.color

[Yaniv]

Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

[Yaniv]

More details about my problem:
I want to change the color of label (Label1.ForeColor which is
system.drawing.color).
I want to take the color from object which has a Uint32 color

Yaniv כתב:

Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

[Yaniv]

More details about my problem:
I want to change the color of label (Label1.ForeColor which is
system.drawing.color).
I want to take the color from object which has a Uint32 color

Yaniv כתב:

Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

[=?ISO-8859-1?Q?G=F6ran_Andersson?=]

Yaniv wrote:

Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

If the integer is representing an argb (alpha+rgb) value, then you can
use the Color.FromArgb(int) method. If it only represents an rgb value,
then you can use Color.FromArgb(int, int), where the first integer is
the alpha value, which you should set to 255 to get a solid color.

--
Göran Andersson
_____
http://www.guffa.com

[Yaniv]

Göran Andersson כתב:

Yaniv wrote:

Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

If the integer is representing an argb (alpha+rgb) value, then you can
use the Color.FromArgb(int) method. If it only represents an rgb value,
then you can use Color.FromArgb(int, int), where the first integer is
the alpha value, which you should set to 255 to get a solid color.

--
Göran Andersson
_____
http://www.guffa.com

Hi

The first option you wrote is not working since the value is Uint32
and not integer as you wrote (I'v got the message "Value of type
'System.UInt32' cannot be converted to 'Integer')

The second option doesn't exist in VB.NET at all (Anyway I can't
convert Uint32 to int.....)
actually I dont know if the Uint32 color is represent argb color or
only rgb color...

[=?UTF-8?B?R8O2cmFuIEFuZGVyc3Nvbg==?=]

Yaniv wrote:

Göran Andersson כתב:

>Yaniv wrote:

>>Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

If the integer is representing an argb (alpha+rgb) value, then you can
use the Color.FromArgb(int) method. If it only represents an rgb value,
then you can use Color.FromArgb(int, int), where the first integer is
the alpha value, which you should set to 255 to get a solid color.

--
Göran Andersson
_____
http://www.guffa.com

Hi

The first option you wrote is not working since the value is Uint32
and not integer as you wrote (I'v got the message "Value of type
'System.UInt32' cannot be converted to 'Integer')

You can just cast the UInt32 to an Int32:

Color color = Color.FromArgb((int)colorValue);

The second option doesn't exist in VB.NET at all (Anyway I can't
convert Uint32 to int.....)

Yes, you are right. There is no such overload to the method. I was
thinking of the Color.FromArgb(int, Color) overload:

Color color = Color.FromArgb(255, Color.FromArgb((int)colorValue));

actually I dont know if the Uint32 color is represent argb color or
only rgb color...

That will be obvious when you try to use it. If it's an rgb value the
top eight bits will be zero, which when used as alpha will make a
completely transparent color.

--
Göran Andersson
_____
http://www.guffa.com

[=?UTF-8?B?R8O2cmFuIEFuZGVyc3Nvbg==?=]

Göran Andersson wrote:

Yaniv wrote:

>Göran Andersson כתב:

>>Yaniv wrote:
Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

If the integer is representing an argb (alpha+rgb) value, then you can
use the Color.FromArgb(int) method. If it only represents an rgb value,
then you can use Color.FromArgb(int, int), where the first integer is
the alpha value, which you should set to 255 to get a solid color.

--
Göran Andersson
_____
http://www.guffa.com

Hi

The first option you wrote is not working since the value is Uint32
and not integer as you wrote (I'v got the message "Value of type
'System.UInt32' cannot be converted to 'Integer')

You can just cast the UInt32 to an Int32:

Color color = Color.FromArgb((int)colorValue);

Sorry, I gave you C# examples.

In VB.NET:

Dim color As Color = Color.FromArgb(CType(colorValue, Int32))

>The second option doesn't exist in VB.NET at all (Anyway I can't
convert Uint32 to int.....)

Yes, you are right. There is no such overload to the method. I was
thinking of the Color.FromArgb(int, Color) overload:

Color color = Color.FromArgb(255, Color.FromArgb((int)colorValue));

Dim color As Color = Color.FromArgb(255,
Color.FromArgb(CType(colorValue, Int32)))

>actually I dont know if the Uint32 color is represent argb color or
only rgb color...

That will be obvious when you try to use it. If it's an rgb value the
top eight bits will be zero, which when used as alpha will make a
completely transparent color.

--
Göran Andersson
_____
http://www.guffa.com

[Armin Zingler]

"Yaniv" <el******@gmail.comschrieb

Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

Dim u As UInt32 = &HFFFFFFFFUI
Dim c As Color

c = Color.FromArgb( _
BitConverter.ToInt32(BitConverter.GetBytes(u), 0) _
)

Armin

[Armin Zingler]

"Göran Andersson" <gu***@guffa.comschrieb

>You can just cast the UInt32 to an Int32:

Color color = Color.FromArgb((int)colorValue);

Sorry, I gave you C# examples.

In VB.NET:

Dim color As Color = Color.FromArgb(CType(colorValue, Int32))

This doesn't work if colorvalue>int32.maxvalue, which is usually the case if
the alpha value 127.

Armin

[=?UTF-8?B?R8O2cmFuIEFuZGVyc3Nvbg==?=]

Armin Zingler wrote:

"Göran Andersson" <gu***@guffa.comschrieb

>>You can just cast the UInt32 to an Int32:

Color color = Color.FromArgb((int)colorValue);

Sorry, I gave you C# examples.

In VB.NET:

Dim color As Color = Color.FromArgb(CType(colorValue, Int32))

This doesn't work if colorvalue>int32.maxvalue, which is usually the
case if the alpha value 127.

Yes, you are right. I tried this in VB, and it won't convert an UInt32
to an Int32 without checking for overflow. It works just fine in C#.
Some say that the CType function in VB is the same as casting in C#, but
obviously it isn't.

I also tried CInt, Convert.ToInt32 and DirectCast, but they all do
overflow checking.

I guess you have to chop up the value in pieces to handle it:

Dim alpha As Integer = colorCode >24
Dim code As Integer = colorCode And &HFFFFFF
Dim c As Color = Color.FromArgb(alpha, Color.FromArgb(code))

or:

Dim alpha As Integer = colorCode >24
Dim red As Integer = (colorCode >16) And &HFF
Dim green As Integer = (colorCode >8) And &HFF
Dim blue As Integer = colorCode And &HFF

Dim c As Color = Color.FromArgb(alpha, red, green, blue)

--
Göran Andersson
_____
http://www.guffa.com

[Armin Zingler]

"Göran Andersson" <gu***@guffa.comschrieb

Armin Zingler wrote:

"Göran Andersson" <gu***@guffa.comschrieb

You can just cast the UInt32 to an Int32:

Color color = Color.FromArgb((int)colorValue);
>
Sorry, I gave you C# examples.
>
In VB.NET:
>
Dim color As Color = Color.FromArgb(CType(colorValue, Int32))

This doesn't work if colorvalue>int32.maxvalue, which is usually
the case if the alpha value 127.

Yes, you are right. I tried this in VB, and it won't convert an
UInt32 to an Int32 without checking for overflow.

I had to try it either before because I wasn't sure. :-)

It works just fine
in C#. Some say that the CType function in VB is the same as casting
in C#, but obviously it isn't.

I also tried CInt, Convert.ToInt32 and DirectCast, but they all do
overflow checking.

Right. Type casting is only valid if one type is derived from the other.
CType does type casting if possible. If not, as in this case, it converts.
Conversion includes overflow checking.

I guess you have to chop up the value in pieces to handle it:

Dim alpha As Integer = colorCode >24
Dim code As Integer = colorCode And &HFFFFFF
Dim c As Color = Color.FromArgb(alpha, Color.FromArgb(code))

or:

Dim alpha As Integer = colorCode >24
Dim red As Integer = (colorCode >16) And &HFF
Dim green As Integer = (colorCode >8) And &HFF
Dim blue As Integer = colorCode And &HFF

Dim c As Color = Color.FromArgb(alpha, red, green, blue)

...and with Option Strict On:

Dim alpha As Integer = CInt(colorCode >24)
Dim red As Integer = CInt(colorCode >16) And &HFF
Dim green As Integer = CInt(colorCode >8) And &HFF
Dim blue As Integer = CInt(colorCode And &HFF)


I think, in Framework 2.0, MSFT should have added an overload of FromARGB
that expects an UInteger, and one overload that uses Byte as the type for A,
R, G, B. Don't know why it's Integer at all (already in <2.0) because
values>255 and <0 don't work anyway.
Armin

[ImageAnalyst]

On Feb 21, 5:00 am, "Yaniv" <[e-mail]:

Hi

How can I convert Uint32 variable to System.drawing.color ??

Thanks in advanced
Yaniv

A side note: Here's a nice web page with all the colors displayed as
color patches:
http://www.pardesiservices.com/softo...colorchart.asp