c# - IDataParameter InvalidCastException -

the microsoft enterprise library data access application block contains following method:

private static idataparameter[] createparametercopy(dbcommand command) {     idataparametercollection parameters = (idataparametercollection)command.parameters;     idataparameter[] parameterarray = new idataparameter[parameters.count];     parameters.copyto(parameterarray, 0);      return cachingmechanism.cloneparameters(parameterarray); } 

if command.parameters tdparametercollection (a teradata .net provider class implements idataparametercollection), parameters.copyto(parameterarray, 0) throws invalidcastexception: "unable cast object of type system.data.idataparameter[] type teradata.client.provider.tdparameter[]".

my first question:

how , why happening?

the exception message suggests parameters have been copied parameterarray, there attempt afterwards convert parameterarray idataparameter[] tdparameter[]. (in case, tdparameter implements idataparameter.)

my second question:

any ideas how fix without using concrete types?

the problem in internal code of copyto method.

msdn says:

the type of source icollection cannot cast automatically type of destination array.

that means array must able convert without explicit conversion. otherwise method call fail.

instead of using copyto, should use foreach , copy them hand 1 one.