问题
How to encode query string space with %20 instead of + ? 
Because System.Web  HttpUtility.UrlEncode() gives the space with +.
回答1:
https://msdn.microsoft.com/en-us/library/system.uri.escapeuristring(v=vs.110).aspx
var encoded = Uri.EscapeUriString("How to encode");
OUTPUT:
How%20to%20encode
来源:https://stackoverflow.com/questions/46336763/c-sharp-net-how-to-encode-url-space-with-20-instead-of