浏览器上的Web控件需要的打印屏幕功能

Question

All,

I have a requirement to enable users of our web page to download jpeg images of the Bing maps that we have put on our forest fire simulation dot net aspx web page. The page in question presently displays a Bing map and up to 96 shapes in as many layers which can take up to 20 seconds to load completely. I could put all these shapes on one layer if it would help - but I an not sure that it would and I thought I would ask here first.

Apparently, any "complicated" client side actions (like ALT-print screen, print from the web page, mwsnap3, or other third party solutions) will not suffice, so I am told to implement a button on the page that will download (or make available) a jpeg image document/image when it is pressed on the page.

I started with a great thread at Convert webpage to image from ASP.NET . ,which is really close to what I want, but the page gets rendered on the browser.ReadyState != WebBrowserReadyState.Complete transition, which fires off before my shapes are loaded on the Bing canvas. I tried to render the page on the DocumentTitleChanged event (and then tried to change the title when my shaped completed loading), but this did not work either.

I tried to force the "Print screen" character with javascript (see Is it possible to simulate key press events programmatically? ), but this translated into a comma (decimal 44) and did not work as expected.

I also see that HTLM5 has some support for this ( http://www.nihilogic.dk/labs/canvas2image ) but while this worked in FireFox, it did not work in IE, which is the browser of choice. I also want to run this on mobile devices, which might not support HTML5 for some time either.

I have a few questions:

1 - Is there another (simple) way to print the contents of the web page that I am missing?

2 - Is there some other WebBrowser event that I can fire that will make more sense)?

3 - Would it help if I stated with some other control then put the maps and shapes on this control for subsequent printing?

4 - Does this go against the grain of web browsing and is just a bad idea (seems that if I can force a 'print screen' then evil web sites could force a Ctrl-Alt-Delete button sequence)?

Thanks - Steve

Answer 1

It might not be an approach you want to do as it will require you to repeat alot of the functionality you already have in a different way but the only truely full proof way to do this is to get the map as an image from the bing maps static imagery service and use GDI+ to draw onto the map yourself then just serve that image direct to the user. Gets round any browser issues but a fair amount of work depending on your requirements:

http://rbrundritt.wordpress.com/2009/02/22/drawing-routes-with-the-ve-web-service/