Edit

Connect to an event hub (.NET)

  • Article

This article shows how to connect to an event hub in different ways by using the .NET SDK. The examples use EventHubProducerClient, which is used to send messages to an event hub. You can use similar variations of constructors for EventHubConsumerClient to consume events from an event hub.

Connect using a connection string

This section shows how to connect to an event hub using a connection string to a namespace or an event hub.

If you have connection string to the namespace and the event hub name, use the EventHubProducerClient constructor that has the connection string and the event hub name parameter.

// Use the constructor that takes the connection string to the namespace and event hub name
producerClient = new EventHubProducerClient(NAMESPACE-CONNECTIONSTRING, EVENTHUBNAME);

Alternatively, you can append ;EntityPath=<EVENTHUBNAME> the namespace's connection string and use the constructor that takes only the connection string.

// Use the constructor that takes the connection string to the namespace and event hub name
producerClient = new EventHubProducerClient(connectionString);

You can also use this constructor if you have a connection string to the event hub (not the namespace).

Connect using a policy name and its key value

The following example shows you how to connect to an event hub using a name and value of the SAS policy you created for an event hub.

//use the constructor that takes AzureNamedKeyCredential parameter
producerClient = new EventHubProducerClient("<NAMESPACENAME>.servicebus.windows.net", "EVENTHUBNAME", new AzureNamedKeyCredential("SASPOLICYNAME", "KEYVALUE"));

Connect using a SAS token

The following example shows you how to connect to an event hub using a SAS token that's generated using a SAS policy.

var token = createToken("NAMESPACENAME.servicebus.windows.net", "SASPOLICYNAME", "KEYVALUE");
producerClient = new EventHubProducerClient("NAMESPACENAME.servicebus.windows.net", "EVENTHUBNAME", new AzureSasCredential(token));

Here's the sample code for generating a token using a SAS policy and key value:

private static string createToken(string resourceUri, string keyName, string key)
{
    TimeSpan sinceEpoch = DateTime.UtcNow - new DateTime(1970, 1, 1);
    var week = 60 * 60 * 24 * 7;
    var expiry = Convert.ToString((int)sinceEpoch.TotalSeconds + week);
    string stringToSign = HttpUtility.UrlEncode(resourceUri) + "\n" + expiry;
    HMACSHA256 hmac = new HMACSHA256(Encoding.UTF8.GetBytes(key));
    var signature = Convert.ToBase64String(hmac.ComputeHash(Encoding.UTF8.GetBytes(stringToSign)));
    var sasToken = String.Format(CultureInfo.InvariantCulture, "SharedAccessSignature sr={0}&sig={1}&se={2}&skn={3}", HttpUtility.UrlEncode(resourceUri), HttpUtility.UrlEncode(signature), expiry, keyName);
    return sasToken;
}

Connect using Microsoft Entra application

  1. Create a Microsoft Entra application.
  2. Assign application's service principal to the appropriate role-based access control (RBAC) role (owner, sender, or receiver). For more information, see Authorize access with Microsoft Entra ID.
var clientSecretCredential = new ClientSecretCredential("TENANTID", "CLIENTID", "CLIENTSECRET");
producerClient = new EventHubProducerClient("NAMESPACENAME.servicebus.windows.net", "EVENTHUBNAME", clientSecretCredential);

Next steps

Review samples on GitHub: