How to get the value of built, encoded ViewState?
"I need to grab the base64-encoded representation of the ViewState. Obviously, this would not be available until fairly late in the request lifecycle, which is OK.
For example, if the output of the page includes:
<input type=""hidden"" name=""__VIEWSTATE""
id=""__VIEWSTATE"" value=""/wEPDwUJODU0Njc5MD...=="" />
I need a way on the server-side to get the value ""/wEPDwUJODU0Njc5MD...==""
To clarify, I need this value when the page is being rendered, not on PostBack. e.g. I need to know the ViewState value that is being sent to the client, not the ViewState I'm getting back from them."