Generic Web API methods for Dynamic CRM in C#

Here are the generalized methods to Create, Retrieve, Update and Delete entity instances in Dynamic CRM using Web API in C#.

It includes method to get httpclient to access Dynamic 365 CRM instance and access token.

Generic Method Definitions for CRUD Operations

// Note : Please provide your Application Id, Client Secret Key, Organization Url and TennantID

//        These parameter can be parameterized, but for simplicity I kept it like that only.

public static async Task<string> GetAccessToken()

{

    var applicationId = "00000000-0000-0000-0000-000000000000";

    var clientSecret = "client-secrete key";

    var organizationUrl = "https://myOrganization.api.crm8.dynamics.com/";

    var aadInstanceUrl = "https://login.microsoftonline.com";

    var tenantId = "00000000-0000-0000-0000-000000000000";

    var clientcred = new ClientCredential(applicationId, clientSecret);

    var authenticationContext = new AuthenticationContext($"{aadInstanceUrl}/{tenantId}");

    var authenticationResult = await authenticationContext.AcquireTokenAsync(organizationUrl, clientcred);

    return authenticationResult.AccessToken;

}

public static HttpClient GetD365Client()

{
    var accessToken = await GetAccessToken();

    var client = new HttpClient();

    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);

    client.DefaultRequestHeaders.Add("OData-MaxVersion", "4.0");

    client.DefaultRequestHeaders.Add("OData-Version", "4.0");

    client.DefaultRequestHeaders.Add("Accept", "application/json");

    client.DefaultRequestHeaders.Add("Prefer", "odata.include-annotations=\"*\"");

    return client;

}

// Note : Please provide your Organization Url

public static string GetOrganizationAPIUrl()

{

    return "https://myOrganization.crm8.dynamics.com/api/data/v9.1/";

}

public static async Task<string> GetEntity(string entityQuery)

{

    string resultJson = null; // Output variable

    var httpClient = CrmHelper.GetD365Client();           

    string organizationAPIUrl = CrmHelper.GetOrganizationAPIUrl();

           

    var httpResponse = await httpClient.GetAsync(organizationAPIUrl + entityQuery);

    if (httpResponse.IsSuccessStatusCode)

    {

        if (httpResponse.StatusCode == System.Net.HttpStatusCode.OK)

        {

            resultJson = httpResponse.Content.ReadAsStringAsync().Result;                   

        }

    }

    return resultJson;

}

public static async Task<string> updateEntity(string entityUri, object crmEntiyObj)

{

    string entityId = null; // Output variable

    var httpClient = await CrmHelper.GetD365Client();

    string organizationAPIUrl = CrmHelper.GetOrganizationAPIUrl();

    HttpRequestMessage updateEntityReq = 
              new HttpRequestMessage(new HttpMethod("PATCH"), organizationAPIUrl + entityUri);

    updateEntityReq.Content = 
              new StringContent(JsonConvert.SerializeObject(crmEntiyObj), Encoding.UTF8, "application/json");

    HttpResponseMessage httpResponseResult = 
              httpClient.SendAsync(updateEntityReq, HttpCompletionOption.ResponseContentRead).Result;

    if (httpResponseResult != null)

    {

        IEnumerable<string> uri = null;

        httpResponseResult.Headers.TryGetValues("OData-EntityId", out uri);

        if (uri != null)

        {

            entityId = uri.FirstOrDefault().Replace(organizationAPIUrl, "");                   

        }

    }

    return entityId;

}

public async Task<string> createEntity(string entityName, object crmEntiyObj)

{           

    string entityId = null; // Output variable

    var httpClient = await CrmHelper.GetD365Client();

    string organizationAPIUrl = CrmHelper.GetOrganizationAPIUrl();

           

    var content = new StringContent(JsonConvert.SerializeObject(crmEntiyObj), Encoding.UTF8, "application/json");

    var httpResponseResult = httpClient.PostAsync(organizationAPIUrl + entityName, content).Result;

    if (httpResponseResult != null)

    {

        IEnumerable<string> uri = null;

        httpResponseResult.Headers.TryGetValues("OData-EntityId", out uri);

        if (uri != null)

        {
            var txtReplacer = organizationAPIUrl + entityName;

            entityId = uri.FirstOrDefault().Replace(txtReplacer, "").Replace("(", "").Replace(")", "");                   

        }

    }

    return entityId;

}

RETRIEVE operation demo:

Please refer here to know more about making canonical for Crm Entity and sending the response in a user-friendly format which other consumer or business can understand.