The KB article you linked offers the printing functionality as a bonus, its main concept is to show how to add buttons to the RadWindow's titlebar. The way this printing works is simply by calling the print() method of the document object of the iframe. This means that we have no control over the printing process and content - this is entirely up to the browser. What I can advise is that you try this code in a simple iframe (with appropriate dimensions, of course). It should produce the same result, as this is what the RadWindow uses.
You can also try the approach from this forum thread
where printing is discussed. The difference is that you would need an additional function to get the HTML from the iframe, yet the results, I expect, will be the same, as the printing functionality comes from the browser, not from our controls.
the Telerik team
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