how can we check file types before uploading them in asp.net?

Posted by LostLord on Stack Overflow See other posts from Stack Overflow or by LostLord
Published on 2010-03-14T00:33:22Z Indexed on 2010/03/14 4:25 UTC
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ASP.NET

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c#

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upload

how can we check file types (formats such as jpg) without using file extensions before -uploading them- in asp.net with c# ?

i am using vs 2008 + asp.net + c# + TELERIK Controls (RadUpload)

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imagine that some body change the text file extension to jpg and select it in a upload conrol such as radupload ...

how can we recognize that this file is truely jpg or not?

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