CODEWITHSUNDEEP
c#asp.netwebformshttphandlerglobal-asax
Matt Cashatt
Matt Cashatt

Reputation: 24208

Using .NET (website project), how can I intercept all incoming image requests and alter their request path?

Thanks for looking.

Background

I have inherited a very old (12 years) .NET website project what uses web form architecture.

This is a very large codebase and, when running on the web server, depends on a very large local resource folder of images. I am working remotely and have been told that the image folder will not be added to the source control; however, I can access it via a network folder (if connected to VPN).

If I hard-code any of the images to use the network path they work fine, but this is obviously not a good solution since there are thousands of images.

Question

Is it possible to intercept any incoming request for an image file and, if the local image folder is not found (i.e. in development on my machine), use the network path URI instead to get the image? If so, what is the correct way to do this?

What I have Tried

I tried intercepting the requests in the Application_BeginRequest method of the global.asax (which I was surprised to find in such an old project) but this does not intercept image requests apparently. My thinking was that I could re-structure the URL there and then comment that code out in production, but this also seems like it wouldn't be a great solution.

Thanks in advance.

Upvotes: 1

Views: 2022

Answers (1)

G0dsquad
G0dsquad

Reputation: 4435

If it's WebForms then you can most certainly use a HTTP Handler to achieve this.

public class ImageHandler : IHttpHandler
{        
    public bool IsReusable
    {
        get
        {
            return false;
        }
    }

    public void ProcessRequest(HttpContext context)
    {
        // Handle your request here, using 
        // context.Request and System.IO 
        // to serve the image from network
    }
}

Then, you'll need to register & configure the Handler in Web.Config like so, for IIS6:

<system.web>
    <httpHandlers>
        <add verb="*" path="*.jpg,*.png" type="Namespace.ImageHandler, AssemblyName" validate="false" />
    </httpHandlers>
</system.web>

Or IIS7:

<system.webServer>
    <handlers>
        <add name="JpgImage" verb="*" path="*.jpg" type="Namespace.ImageHandler, AssemblyName" resourceType="File" />
        <add name="PngImage" verb="*" path="*.png" type="Namespace.ImageHandler, AssemblyName" resourceType="File" />
    </handlers>
</system.webServer>

Upvotes: 3

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