where generic type parameters and constraints

private void Insertdata<trowmetadata, Tfieldmetadata, tcellmetadata> (Imetadatareader<trowmetadata, Tfieldmetadata, tcellmetadata> DataSource, Int16 Planpartitionid, bool loadblankdata)
where Trowmetadata:irowmetadata, New ()
where Tfieldmetadata:new ()
where Tcellmetadata:icellmetadata, New ()
{

}

Where trowmetadata:irowmetadata means that the Trowmetadata parameter must implement an interface Irowmetadata

Where tcellmetadata:icellmetadata means that the Tcellmetadata parameter must implement an interface Icellmetadata

Trowmetadata, Tfieldmetadata, tcellmetadata the new () after three parameter refers to a public constructor that must have no arguments

Http://www.cnblogs.com/wanghonghu/archive/2012/07/11/2586920.html

where generic type parameters and constraints