Byte array output as an Image

Question

I know it is be possible to do this:

<asp:Image runat="server" ImageUrl="~/MyImageHandler.ashx?imageid=2" />

...but I have a case where the byte array data is only available to the Page (ie, not available in the session, and cannot be referenced by an id) so I can't point the ImageUrl to a different page.

Is there a way of giving an asp:Image the byte array to render as an Image?

Answer 1

The only decent solution to this is to put the byte array in session. If you're concerned about uniqueness (multiple people getting each other's byte arrays), use a random GUID as the key.

Answer 2

The major hurtle you're going to have to deal with is that an <asp:Image/> element gets rendered as a regular <img />, which needs a src attribute that points at a URL.

That being the case, I see two hairy alternatives:

• Use the technique described here to embed your image encoded in Base64 in the src attribute. Note that this does not work with Internet Explorer.

• Embed your Base64-encoded image into the page as a hidden <input /> element. You could then use JavaScript to POST that data back to the server, which would just send it back to the browser using Response.Write() (being sure to set the Content-Type appropriately, of course).