Images Stored In Database

[Fitz]

Hi

Is it possible to get the RadRotator control to reference images that are stored in a SQL Server 2008 database, rather than in the file system itself?

Any help or code segments would be appreciated.

Regards
Fitz

[Fiko]

Hi Fitz,

Yes you can achieve this by using the same approach as with local images. There is only one difference when you use images stored in DB. Instead the path ( the value of the src property of the image) of an image you need to use the path to a handler that gets the image from the database and returns it to the browser. For example instead of "/images/image1.jpg" you need to use "ImageHandler.aspx?image=image1.jpg" . In this handler you should process the image from the DB ( depending the query) and return it to the browser. The implementation of this handler is a common programming task and it is not related to the RadRotator control. You can check the following Google search for more details.

Greetings,
Fiko
the Telerik team

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[ManniAT]

By the way,

a tip how I solve this.
First of all - I hate this "handler id passing" :)

So I wrote a http handler and bound it to a "not used" extension in web.config

<add path="*.jpeg" verb="GET" type="MyApp.Namespace.JPEGHandler" validate="false" />

In the handler I get the filename (path) and use it as a search criteria for DB access.

    public class JPEGHandler : IHttpHandler {

        public void ProcessRequest(HttpContext context) {
            HttpResponse hR = context.Response;
            string strFileName = Path.GetFileNameWithoutExtension(context.Request.FilePath).ToLower();
            //you could also split the path a bit more for to address differnt tables / colums in your database
            // /Customers/Locations/MyCust.jpeg could mean
            // take the Location image from the customers -- where customername==MyCust
            // OR /Employees/Portrait/Joe.jpeg
            // takte the portrait from employees -- where employeename==Joe

            //for demonstration purposes I "produce" my image instead of loading it from database
            Bitmap bmpRet = new Bitmap(130, 130);
            bmpRet.SetResolution(96, 96);
            Graphics gR = Graphics.FromImage(bmpRet);
            gR.DrawString(strFileName, SystemFonts.DefaultFont, Brushes.Red, 3, 3);
            gR.Dispose();
            hR.Clear();
            //important to set the correct mime type
            hR.ContentType = "image/jpg";
            //cache duration depends on your DB changes
            hR.Cache.SetExpires(DateTime.Now.AddSeconds(3));
            hR.Cache.SetCacheability(HttpCacheability.Public);
            hR.Cache.SetValidUntilExpires(true);
            hR.BufferOutput = true;
            bmpRet.Save(hR.OutputStream, ImageFormat.Jpeg);
            bmpRet.Dispose();
            hR.Flush();
        }

        public bool IsReusable {
            get {
                return false;
            }
        }
    }

This approach is SEO friendly out of the box.
.../Handler.ashx?ImgID=XVR33 is not that good for search engines as if you write
../Cutomers/Microsoft.jpeg

A last thing - you have to tell IIS that it should process requests to (in this case) JPEG (and ensure that check for existing file is NOT set).

And as Fiko said - getting an image from the DB hast nothing to do with RAD-(or other) controls.
Which means - you can also use such "image paths" anywhere in your app.
Things like <img src="/Customers/TomTom.jpeg"... will also work with an approach like this.

Maybe I could help a little with this idea.
Regards

Manfred

[Fiko]

Hello Manfred,

Thank you for sharing this code. I believe it will be useful for other members of our community that have such task.

Sincerely yours,
Fiko
the Telerik team

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[ManniAT]

You are welcome :)

By the way - one of the reasons why I implemented this are forums.
For serveral reasons it is sometimes nice to provide "live data" in such forums.
BUT (of course) IFRAMES are normaly disabled - but most of the time you can post images.

So with a bit intelligent caching you can provide "live information" via posting an image.

A scenario I had (just to provide an example):
Our WoW guild planed a meeting.
I was involved in planing - to make things easier I made a little DB app where I stored the reservations the
the payment status and such things.

Our main communication platform is PHBB - so I had to decide if I would
a.) Maintain a website with registration and so on
OR
b.) Use the existing infrastructure (our PHBB forum)

Of course b.) was the decission. And to provide actual information I opened a thread and linked such a "jpeg image".
On my server I took the data made a simple list and provided this as image.

After closing the reservation / payment - I saved a copy of this image to disk - and changed my link in the post from XXX.jpEg to xxx.jpg.
So the final result is visible "for ever" :)

The same thing I do for "temperature logging" of my server room.
I draw the temperature lines to an image - and even with the most simple browser (mobile phone as an example) I can view the current situation in my serverroom.

This was my first project using this technology - the reason - my mobile phone did not display images when the path was not an "image path" - so ../ShowImg.aps?ID=123 did not display -- ../123.jpeg does.

Regards

Manfred