WCF: How to pass a variable number of parameters to a WebGet enabled service

Question

We're trying to pass a variable number of key-value-pairs to our service by using the WebGetAttribute and the UriTemplate to expose a REST interface. What we want to do:

[WebGet(UriTemplate="/Query/Select?{query}"]
Response Query(string query);

At client-side we want to specify some keys several times, e.g.:
hllp://localhost/MyService/Query/Select?field=Name&fieldsort=asc&field=ID

Our first approach was to use the following UriTemplate and to decompose the key-value-pairs manually:

[WebGet(UriTemplate="/Query/{*query}"]
ResponseQuery(string query);

But this just applies to segments and so URLs like
hllp://localhost/MyService/Query/field=Val%3Due get automatically decoded by WCF and "field=Val=ue" will be passed to the Service method.

Even worse, double encoded URLs get fully decoded, too:
hllp://localhost/MyService/Query/field=Val%253Due becomes "field=Val=ue" again.

Is there any way, to access the raw query string? If not, can we extend/use UriTemplate in another way, to work with a dynamic number of key-value-pairs?

Answer 1

Using WebOperationContext.Current enabled us to get the raw query string, which will now be parsed by ourself.