为什么在Dynamics 365 XRM工具SDK中使用IOrganizationService而不是CrmServiceClient？

Question

Microsoft sample code for accessing Dynamics often looks like this:

    static void Main(string[] args)
    {
        try
        {
            string connectionString =
                "Url=https://myorg.crm.dynamics.com; Username=me@myorg.com; Password=******; authtype=Office365";

            using (CrmServiceClient conn = new CrmServiceClient(connectionString))
            {
                // Cast the proxy client to the IOrganizationService interface.
                IOrganizationService orgService = (IOrganizationService)conn.OrganizationWebProxyClient ??
                                                  conn.OrganizationServiceProxy;

                Console.WriteLine("Microsoft Dynamics CRM version {0}.", ((RetrieveVersionResponse)orgService.Execute(new RetrieveVersionRequest())).Version);
            }
        }
        catch (FaultException<OrganizationServiceFault> osFaultException)
        {
            Console.WriteLine("Fault Exception caught");
            Console.WriteLine(osFaultException.Detail.Message);
        }
        catch (Exception e)
        {
            Console.WriteLine("Uncaught Exception");
            Console.WriteLine(e);
        }
    }
}

But it is equally possible (and simpler) to use the Crm Service Client directly, like this:

class Program
{
    static void Main(string[] args)
    {
        try
        {
            string connectionString =
                "Url=https://myorg.crm.dynamics.com; Username=me@myorg.com; Password=******; authtype=Office365";

            using (CrmServiceClient conn = new CrmServiceClient(connectionString))
            {
                Console.WriteLine("Microsoft Dynamics CRM version {0}.", ((RetrieveVersionResponse)conn.Execute(new RetrieveVersionRequest())).Version);
            }
        }
        catch (FaultException<OrganizationServiceFault> osFaultException)
        {
            Console.WriteLine("Fault Exception caught");
            Console.WriteLine(osFaultException.Detail.Message);
        }
        catch (Exception e)
        {
            Console.WriteLine("Uncaught Exception");
            Console.WriteLine(e);
        }
    }
}

My question: Why use that IOrganizationService property ever? It seems as if it has only a subset of the functionality of the CrmServiceClient. And CrmServiceClient used directly seems both faster, simpler, more efficient, and more feature-rich.

Any idea about why the sample code always has this additional layer of indirection?

Thanks.

Answer 1

IOrganizationService is an interface that defines the most basic methods required to access all Dynamics functions. There are a number of general benefits to using interfaces.

IOrganizationService has been around since CRM 2011, whilst CrmServiceClient was introduced around CRM 2016. A simple reason for using IOrganizationService is that has been around much longer and is present in existing code bases.

CrmServiceClient implements IOrganizationService , and also provides a range of other methods, eg authenticating with CRM. Before CrmServiceClient was introduced we used CrmConnection to authenticate to CRM. When we had to migrate from CrmConnection to CrmServiceClient , we only had to change to CrmServiceClient , extract IOrganizationService and the rest of the code base remains the same.

Programming to the IOrganizationService interface makes your code far more portable, and reusable. For example; when you don't know your service object is going to be created.

IOrganizationService orgService = IOrganizationService)conn.OrganizationWebProxyClient ?? conn.OrganizationServiceProxy;

For testing purposes when you want to mock IOrganizationService with a new MockOrganizationService class.

When you want to move code between an external application and a plugin. In a plugin the CrmServiceClient is not provided.