How do i get to SForceService using dotnet Core framework

@Sathishkumar Balakrishnan

this is an old post and you may have the answer by now but I came across this problem only this week. 

For Partner API, SforceService class is replaced by Soap (interface) and SoapClient (implementing class) 

For Metadata API, use the MetadataPortType interface and MetadataPortTypeClient implementing class 

For Tooling API, use the SforceServicePortType interface and SforceServicePortTypeClient implementing class. 

The previous methods that were unavailable may now just be the async equivalents. For example, instead of describeSObjects(sObjectType) for Partner API you have describeSObjectsAsync(describeSObjectsRequest) where describeSObjectsRequest has a sObjectType field.