Generic Implementation for Paging Class in c#
Some quick remarks:


Names shouldn't contain underscores etc: CountingCloud_DevContext. (The exception is the underscore at the start of a private member (e.g. _dbContext.)
If you have a Dictionary, do not use ContainsKey if you need to retrieve the value associated with that key. This is why the much more efficient TryGetValue exists.
Do not copy-paste magic strings (e.g. "PageSize") all over the place. Store them as const in a relevant class and use that.
But most importantly: what's the point of Dictionary&lt;string, object&gt; when all it contains is two specific key-value pairs? Why not make a PagingParameters class with PageSize and PageStart as nullable ints? Don't make things too generic, because all you end up is making things harder for yourself.
Also avoid making a generic Repository class. It likely will create more work and solve nothing.