Creation of semi-transparent filled polygons?

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I have relatively little experience in Dot Net graphics.

I have a picturebox with a background image. For the purpose of this
application it is necessary to draw polygons (both filled and outline only)
to emphasize parts of the image. It would probably be better if the
background image remained at least partly visible.

Is there any simple way to generate a semi-transparent filled polygon?
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Re: Creation of semi-transparent filled polygons? by Bob

Bob
Thu Sep 30 03:02:22 CDT 2004

Just draw the shape you like with a brush that has an alpha component.

//in the Paint handler...
SolidBrush b=new SolidBrush(Color.FromArgb(128,Color.Red));
e.Graphics.FillRectangle(10,10,100,150);

HTH.

--
Bob Powell [MVP]
Visual C#, System.Drawing

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"B. Chernick" <BChernick@discussions.microsoft.com> wrote in message
news:B8D4006D-CF92-4766-B56E-9DA0D2AEC96D@microsoft.com...
> I have relatively little experience in Dot Net graphics.
>
> I have a picturebox with a background image. For the purpose of this
> application it is necessary to draw polygons (both filled and outline
only)
> to emphasize parts of the image. It would probably be better if the
> background image remained at least partly visible.
>
> Is there any simple way to generate a semi-transparent filled polygon?


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Re: Creation of semi-transparent filled polygons? by BChernick

BChernick
Thu Sep 30 20:49:03 CDT 2004

Perfect. Thanks!

(Things have changed a little since I learned how to draw lines in
TurboPascal class.)

"Bob Powell [MVP]" wrote:

> Just draw the shape you like with a brush that has an alpha component.
>
> //in the Paint handler...
> SolidBrush b=new SolidBrush(Color.FromArgb(128,Color.Red));
> e.Graphics.FillRectangle(10,10,100,150);
>
> HTH.
>
> --
> Bob Powell [MVP]
> Visual C#, System.Drawing
>
> Answer those GDI+ questions with the GDI+ FAQ
> http://www.bobpowell.net/gdiplus_faq.htm
>
> The GDI+ FAQ RSS feed: http://www.bobpowell.net/faqfeed.xml
> Windows Forms Tips and Tricks RSS: http://www.bobpowell.net/tipstricks.xml
> Bob's Blog: http://bobpowelldotnet.blogspot.com/atom.xml
>
>
>
>
>
>
> "B. Chernick" <BChernick@discussions.microsoft.com> wrote in message
> news:B8D4006D-CF92-4766-B56E-9DA0D2AEC96D@microsoft.com...
> > I have relatively little experience in Dot Net graphics.
> >
> > I have a picturebox with a background image. For the purpose of this
> > application it is necessary to draw polygons (both filled and outline
> only)
> > to emphasize parts of the image. It would probably be better if the
> > background image remained at least partly visible.
> >
> > Is there any simple way to generate a semi-transparent filled polygon?
>
>
>
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