title: Setting/removing CS_DROPSHADOW style for a WinForms form dynamically (C#)
body: <p>How to do that? I could not find any useful sample for C#. I know I should use SetClassLong/SetClassLongPtr, but here is the definition I only found: <a href="http://www.pinvoke.net/default.aspx/user32/SetClassLongPtr.html" rel="nofollow">http://www.pinvoke.net/default.aspx/user32/SetClassLongPtr.html</a>.</p>
  
  <p>Obviously, I should call GetClassLongPtr with GCL_STYLE to read the current style flags, add or exclude CS_DROPSHADOW, and then call SetClassLongPtr with the changed flag value. But looking at that PInvoke definition, it is not trivial, especially taking into account 32/64-bit systems.</p>
  
  <p>Can anybody give a link or a good example of this? And please, do not provide samples with overwriting CreateParams as this does not work for our dynamic scenario. Maybe, there is another [managed] way to do that?</p>