将对象传递给WCF服务调用C＃

Question

我很难理解如何调用以下WCF服务。

public class Product : Proactive.Product.ProductDataServiceClient
{
    public GetProductSellableResponse getProductSellable(GetProductSellableRequest _GetProductSellableRequest)
    {

        GetProductSellableResponse rep = new GetProductSellableResponse();

        return rep;
    }
}

如何将GetProductSellableRequest对象传递给调用？我只是发送XML吗？