How to quickly connect to Dynamics CRM/365 (online-onprem) using C#?

Note: for this walkthrough I’ve been using ConsoleApplication

Step 1: Add following .Net references:

        System.Runtime.Serialization

      System.ServiceModel

Step 2: Add following references available in Bin folder of the SDK

        Microsoft.Xrm.Sdk

      Microsoft.Crm.Sdk.Portal

Step 3: Add following namespaces in your class file 

      using System.Runtime.Serialization;

      using System.ServiceModel;

      using System.ServiceModel.Description;

      using Microsoft.Xrm.Sdk;

      using Microsoft.Xrm.Sdk.Client;

      using Microsoft.Xrm.Sdk.Query;

      using Microsoft.Xrm.Sdk.Discovery;

      using Microsoft.Crm.Sdk.Messages;

Step 4: Create a method EstablishConnetionWithCRM with following three parameters:
       UserName - Provide O365 Userid in case of online CRM, for on-prem proivde doamin\username
       Password - Provide Password
      ServiceUrl - Provide Organization Service URL by going through following path in CRM
Microsoft Dynamics CRM > Settings > Customization > Developer Resources > Service Endpoints > Organization Service

Step 5: Your EstablishConnetionWithCRM method should look like following:

Public static void EstablishConnetionWithCRM(string UserName, string Password, string ServiceUrl){

try{

                ClientCredentials credentials = new ClientCredentials();

                credentials.UserName.UserName = UserName;

                credentials.UserName.Password = Password;

                Uri serviceUri = new Uri(ServiceUrl);

                OrganizationServiceProxy sp = new OrganizationServiceProxy(serviceUri, null, credentials, null);

                sp.EnableProxyTypes();

                _service = (IOrganizationService)sp;

            }

            catch (Exception ex)

            {

                Console.WriteLine("Error: " + ex.Message);

            }

}

Step 6: Call EstablishConnetionWithCRM into the Main method and check if you are connected or not:

static void Main(string[] args)

        {

            EstablishConnetionWithCRM ("<USERNAME>", "<PASSWORD>", "https://<DOMAIN>/XRMServices/2011/Organization.svc");

            Guid userId = ((WhoAmIResponse)_service.Execute(new WhoAmIRequest())).UserId;

            if (userId != Guid.Empty)

                Console.WriteLine("Connection Established Successfully");

              Else

                Console.WriteLine("Connection was not Established");

            Console.ReadLine();

        }

Final code will be following

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Runtime.Serialization;

using System.ServiceModel;

using System.ServiceModel.Description;

using Microsoft.Xrm.Sdk;

using Microsoft.Xrm.Sdk.Client;

using Microsoft.Xrm.Sdk.Query;

using Microsoft.Xrm.Sdk.Discovery;

using Microsoft.Crm.Sdk.Messages;

namespace connecToCRM

{

    class Program

    {

        static IOrganizationService _service;

        static void Main(string[] args)

        {

            EstablishConnetionWithCRM ("<USERNAME>", "<PASSWORD>", "https://<DOMAIN>/XRMServices/2011/Organization.svc");

            Guid userId = ((WhoAmIResponse)_service.Execute(new WhoAmIRequest())).UserId;

            if (userId != Guid.Empty)

                Console.WriteLine("Connection Established Successfully");

              Else

                Console.WriteLine("Connection was not Established");

            Console.ReadLine();

        } //End of Main

        Public static void EstablishConnetionWithCRM(string UserName, string Password, string ServiceUrl){

try{

                ClientCredentials credentials = new ClientCredentials();

                credentials.UserName.UserName = UserName;

                credentials.UserName.Password = Password;

                Uri serviceUri = new Uri(ServiceUrl);

                OrganizationServiceProxy sp = new OrganizationServiceProxy(serviceUri, null, credentials, null);

                sp.EnableProxyTypes();

                _service = (IOrganizationService)sp;

            }

            catch (Exception ex)

            {

                Console.WriteLine("Error: " + ex.Message);

            }

}//End of EstablishConnetionWithCRM function

    } //End of Class

}//End of namespace

~~YOU ARE DONE, ENJOY~~