Dropping custom graphic on a page

[Rob Lowney]

Good Day,

I am creating a GIF image on the fly via code and end up with a bitmap object.
I now need to place the image on a web page.

Currently I'm using the save method to save it to disk with a unique file
name then displaying that file name in a regular old image. I would like
to find a way to place the image on the screen without first having to save
a file on the file system. Does anybody have any ideas/sample code on how
to get this done?

Thanks,

Rob.

[Constance J. Petersen]

Hi Rob,

"Rob Lowney" <rob.lowney@xwave.com> wrote in message
news:3b5b1fc0$1@news.devx.com...
> I am creating a GIF image on the fly via code and end up with a bitmap
object.
> I now need to place the image on a web page.
> Currently I'm using the save method to save it to disk with a unique file
> name then displaying that file name in a regular old image. I would like
> to find a way to place the image on the screen without first having to
save
> a file on the file system. Does anybody have any ideas/sample code on how
> to get this done?

I've done this by first saving the image, as you have. Because the page it's
going to is HTML based, it stands to reason that you would need to first
save the file in a browser compatible format such as gif, jpg, or png.
--
Constance Petersen, DevX newsgroup section leader
SoftMedia Artisans, Inc.
http://www.smartisans.com
Visual Basic.NET Internet Black Book
ISBN: 1-58880-078-4

[Rob Lowney]

"Constance J. Petersen" <constance@smartisans.com> wrote:
>Hi Rob,
>
>"Rob Lowney" <rob.lowney@xwave.com> wrote in message
>news:3b5b1fc0$1@news.devx.com...
>> I am creating a GIF image on the fly via code and end up with a bitmap
>object.
>> I now need to place the image on a web page.
>> Currently I'm using the save method to save it to disk with a unique file
>> name then displaying that file name in a regular old image. I would like
>> to find a way to place the image on the screen without first having to
>save
>> a file on the file system. Does anybody have any ideas/sample code on
how
>> to get this done?
>
>I've done this by first saving the image, as you have. Because the page
it's
>going to is HTML based, it stands to reason that you would need to first
>save the file in a browser compatible format such as gif, jpg, or png.

I am doing this now... Saving as a GIF. I want to do this without first
saving the image to disk, thus not having to give the user write access to
the system.

[Russell Jones]

You can avoid saving the image to disk by following this procedure:

1. Write the image tag out with its src attribute containing a URL back to
your WebForm, for example, if your WebForm is
http://yourServer/yourApp/somePage.aspx, you could use the URL
http://yourServer/yourApp/somePage.aspx?getImage=True

The browser will then call the src URL to get the image data, which will
execute your page for the second time. You can tell the difference by
checking in the Page_Load event for the getImage QueryString value. If it's
"True" then create and return the image by setting the ResponseType to
image/gif (or whatever file format you're creating). Then, create the
graphic and Save it to the Response object. For example, this line sends a
bitmap to the client as a GIF-formatted image:

bmp.Save(Response.OutputStream, imgFormat.Gif)

Russell Jones
Sr. Web Development Editor,
DevX.com


"Rob Lowney" <rob.lowney@xwave.com> wrote in message
news:3b5c2116$1@news.devx.com...
>
> "Constance J. Petersen" <constance@smartisans.com> wrote:
> >Hi Rob,
> >
> >"Rob Lowney" <rob.lowney@xwave.com> wrote in message
> >news:3b5b1fc0$1@news.devx.com...
> >> I am creating a GIF image on the fly via code and end up with a bitmap
> >object.
> >> I now need to place the image on a web page.
> >> Currently I'm using the save method to save it to disk with a unique
file
> >> name then displaying that file name in a regular old image. I would
like
> >> to find a way to place the image on the screen without first having to
> >save
> >> a file on the file system. Does anybody have any ideas/sample code on
> how
> >> to get this done?
> >
> >I've done this by first saving the image, as you have. Because the page
> it's
> >going to is HTML based, it stands to reason that you would need to first
> >save the file in a browser compatible format such as gif, jpg, or png.
>
> I am doing this now... Saving as a GIF. I want to do this without first
> saving the image to disk, thus not having to give the user write access to
> the system.

[Rob Lowney]

Perfect... Works like a charm.

Thanks.

Rob


"Russell Jones" <arj1@northstate.net> wrote:
>You can avoid saving the image to disk by following this procedure:
>
>1. Write the image tag out with its src attribute containing a URL back
to
>your WebForm, for example, if your WebForm is
>http://yourServer/yourApp/somePage.aspx, you could use the URL
>http://yourServer/yourApp/somePage.aspx?getImage=True
>
>The browser will then call the src URL to get the image data, which will
>execute your page for the second time. You can tell the difference by
>checking in the Page_Load event for the getImage QueryString value. If it's
>"True" then create and return the image by setting the ResponseType to
>image/gif (or whatever file format you're creating). Then, create the
>graphic and Save it to the Response object. For example, this line sends
a
>bitmap to the client as a GIF-formatted image:
>
>bmp.Save(Response.OutputStream, imgFormat.Gif)
>
>Russell Jones
>Sr. Web Development Editor,
>DevX.com

[Constance J. Petersen]

Hi Russell,

"Russell Jones" <arj1@northstate.net> wrote in message
news:3b5c69e1$1@news.devx.com...
> bmp.Save(Response.OutputStream, imgFormat.Gif)

Very cool!
--
Constance Petersen, DevX newsgroup section leader
SoftMedia Artisans, Inc.
http://www.smartisans.com
Visual Basic.NET Internet Black Book
ISBN: 1-58880-078-4