Using WPF to Generate an Image

[Tem]

I'm still trying to figure out how to do this simple task with WPF.
I need to draw a black circle using WPF and generate an image file. (gif or
png)

Any help is greatly appreciated.

Tem

I used the following but it resulted in a blank file. I cannot figure out
what is wrong with it.

RenderTargetBitmap rtb = new RenderTargetBitmap(200, 200, 96, 96,
PixelFormats.Pbgra32);

Ellipse cir = new Ellipse();
cir.Height = 50;
cir.Width = 50;
cir.Stroke = Brushes.Black;
cir.StrokeThickness = 1.0;

rtb.Render(cir);

PngBitmapEncoder png = new PngBitmapEncoder();
png.Frames.Add(BitmapFrame.Create(rtb));
using (Stream fs= File.Create("test.png"))
{
png.Save(fs);
}

[Willy Denoyette [MVP]]

"Tem" <te*****@yahoo.comwrote in message
news:u9*************@TK2MSFTNGP06.phx.gbl...

I'm still trying to figure out how to do this simple task with WPF.
I need to draw a black circle using WPF and generate an image file. (gif
or png)

Any help is greatly appreciated.

Tem

I used the following but it resulted in a blank file. I cannot figure out
what is wrong with it.

RenderTargetBitmap rtb = new RenderTargetBitmap(200, 200, 96, 96,
PixelFormats.Pbgra32);

Ellipse cir = new Ellipse();
cir.Height = 50;
cir.Width = 50;
cir.Stroke = Brushes.Black;
cir.StrokeThickness = 1.0;

rtb.Render(cir);

PngBitmapEncoder png = new PngBitmapEncoder();
png.Frames.Add(BitmapFrame.Create(rtb));
using (Stream fs= File.Create("test.png"))
{
png.Save(fs);
}

You are missing something like:

cir.Arrange(new Rect(new Size(50, 50)));

Note that you might get quicker answers when you consult (and post) to the
msdn WPF forum first
http://forums.microsoft.com/MSDN/Sho...D=119&SiteID=1

Willy.

[Tem]

Thank you so much, I got it to work.

Another simple question:
I need to add another circle, slightly smaller, 45 in diameter to the same
image. the final image should be a ring.
What would be the command to add another shape?

Here's my code:

RenderTargetBitmap rtb = new RenderTargetBitmap(200, 200, 96,
96,PixelFormats.Pbgra32);

Ellipse cir = new Ellipse();
cir.Height = 50;
cir.Width = 50;
cir.Stroke = Brushes.Black;
cir.StrokeThickness = 1.0;

cir.Arrange(new Rect(new Size(50, 50)));

rtb.Render(cir);

PngBitmapEncoder png = new PngBitmapEncoder();
png.Frames.Add(BitmapFrame.Create(rtb));
using (Stream fs= File.Create("test.png"))
{
png.Save(fs);
}

[Willy Denoyette [MVP]]

"Tem" <te*****@yahoo.comwrote in message
news:OK**************@TK2MSFTNGP05.phx.gbl...

Thank you so much, I got it to work.

Another simple question:
I need to add another circle, slightly smaller, 45 in diameter to the same
image. the final image should be a ring.
What would be the command to add another shape?

Here's my code:

RenderTargetBitmap rtb = new RenderTargetBitmap(200, 200, 96,
96,PixelFormats.Pbgra32);

Ellipse cir = new Ellipse();
cir.Height = 50;
cir.Width = 50;
cir.Stroke = Brushes.Black;
cir.StrokeThickness = 1.0;

cir.Arrange(new Rect(new Size(50, 50)));

rtb.Render(cir);

PngBitmapEncoder png = new PngBitmapEncoder();
png.Frames.Add(BitmapFrame.Create(rtb));
using (Stream fs= File.Create("test.png"))
{
png.Save(fs);
}

Draw a new ellipse inside the first one and render.

...
rtb.Render(cir);
cir.Height = 45;
cir.Width = 45;
cir.Arrange(new Rect(new Size(50, 50)));
rtb.Render(cir);
....

Willy.

[Serge Baltic]

Hello,

Note that you might get quicker answers when you consult (and post)
to the msdn WPF forum first
http://forums.microsoft.com/MSDN/Sho...D=119&SiteID=1

What's the NNTP address for that forum?

(H) Serge

[Laurent Bugnion, MVP]

Hi,

Serge Baltic wrote:

Hello,

>Note that you might get quicker answers when you consult (and post)
to the msdn WPF forum first
http://forums.microsoft.com/MSDN/Sho...D=119&SiteID=1

What's the NNTP address for that forum?

(H) Serge

There is none. It's unfortunate, but Microsoft is slowly pulling out of
NNTP and keeping all the forums on the web. There is a RSS feed though.

HTH,
Laurent
--
Laurent Bugnion [MVP ASP.NET]
Software engineering, Blog: http://www.galasoft.ch
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