AWS SDK Version 3 for .NET
API Reference

AWS services or capabilities described in AWS Documentation may vary by region/location. Click Getting Started with Amazon AWS to see specific differences applicable to the China (Beijing) Region.

Container for the parameters to the SendMessage operation. Delivers a message to the specified queue.

A message can include only XML, JSON, and unformatted text. The following Unicode characters are allowed:

#x9 | #xA | #xD | #x20 to #xD7FF | #xE000 to #xFFFD | #x10000 to #x10FFFF

Any characters not included in this list will be rejected. For more information, see the W3C specification for characters.

Inheritance Hierarchy

System.Object
  Amazon.Runtime.AmazonWebServiceRequest
    Amazon.SQS.AmazonSQSRequest
      Amazon.SQS.Model.SendMessageRequest

Namespace: Amazon.SQS.Model
Assembly: AWSSDK.SQS.dll
Version: 3.x.y.z

Syntax

C#
public class SendMessageRequest : AmazonSQSRequest
         IAmazonWebServiceRequest

The SendMessageRequest type exposes the following members

Constructors

NameDescription
Public Method SendMessageRequest()

Empty constructor used to set properties independently even when a simple constructor is available

Public Method SendMessageRequest(string, string)

Instantiates SendMessageRequest with the parameterized properties

Properties

NameTypeDescription
Public Property DelaySeconds System.Int32

Gets and sets the property DelaySeconds.

The length of time, in seconds, for which to delay a specific message. Valid values: 0 to 900. Maximum: 15 minutes. Messages with a positive DelaySeconds value become available for processing after the delay period is finished. If you don't specify a value, the default value for the queue applies.

When you set FifoQueue, you can't set DelaySeconds per message. You can set this parameter only on a queue level.

Public Property MessageAttributes System.Collections.Generic.Dictionary<System.String, Amazon.SQS.Model.MessageAttributeValue>

Gets and sets the property MessageAttributes.

Each message attribute consists of a Name, Type, and Value. For more information, see Amazon SQS message attributes in the Amazon SQS Developer Guide.

Public Property MessageBody System.String

Gets and sets the property MessageBody.

The message to send. The minimum size is one character. The maximum size is 256 KiB.

A message can include only XML, JSON, and unformatted text. The following Unicode characters are allowed:

#x9 | #xA | #xD | #x20 to #xD7FF | #xE000 to #xFFFD | #x10000 to #x10FFFF

Any characters not included in this list will be rejected. For more information, see the W3C specification for characters.

Public Property MessageDeduplicationId System.String

Gets and sets the property MessageDeduplicationId.

This parameter applies only to FIFO (first-in-first-out) queues.

The token used for deduplication of sent messages. If a message with a particular MessageDeduplicationId is sent successfully, any messages sent with the same MessageDeduplicationId are accepted successfully but aren't delivered during the 5-minute deduplication interval. For more information, see Exactly-once processing in the Amazon SQS Developer Guide.

  • Every message must have a unique MessageDeduplicationId,

    • You may provide a MessageDeduplicationId explicitly.

    • If you aren't able to provide a MessageDeduplicationId and you enable ContentBasedDeduplication for your queue, Amazon SQS uses a SHA-256 hash to generate the MessageDeduplicationId using the body of the message (but not the attributes of the message).

    • If you don't provide a MessageDeduplicationId and the queue doesn't have ContentBasedDeduplication set, the action fails with an error.

    • If the queue has ContentBasedDeduplication set, your MessageDeduplicationId overrides the generated one.

  • When ContentBasedDeduplication is in effect, messages with identical content sent within the deduplication interval are treated as duplicates and only one copy of the message is delivered.

  • If you send one message with ContentBasedDeduplication enabled and then another message with a MessageDeduplicationId that is the same as the one generated for the first MessageDeduplicationId, the two messages are treated as duplicates and only one copy of the message is delivered.

The MessageDeduplicationId is available to the consumer of the message (this can be useful for troubleshooting delivery issues).

If a message is sent successfully but the acknowledgement is lost and the message is resent with the same MessageDeduplicationId after the deduplication interval, Amazon SQS can't detect duplicate messages.

Amazon SQS continues to keep track of the message deduplication ID even after the message is received and deleted.

The maximum length of MessageDeduplicationId is 128 characters. MessageDeduplicationId can contain alphanumeric characters (a-z, A-Z, 0-9) and punctuation (!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~).

For best practices of using MessageDeduplicationId, see Using the MessageDeduplicationId Property in the Amazon SQS Developer Guide.

Public Property MessageGroupId System.String

Gets and sets the property MessageGroupId.

This parameter applies only to FIFO (first-in-first-out) queues.

The tag that specifies that a message belongs to a specific message group. Messages that belong to the same message group are processed in a FIFO manner (however, messages in different message groups might be processed out of order). To interleave multiple ordered streams within a single queue, use MessageGroupId values (for example, session data for multiple users). In this scenario, multiple consumers can process the queue, but the session data of each user is processed in a FIFO fashion.

  • You must associate a non-empty MessageGroupId with a message. If you don't provide a MessageGroupId, the action fails.

  • ReceiveMessage might return messages with multiple MessageGroupId values. For each MessageGroupId, the messages are sorted by time sent. The caller can't specify a MessageGroupId.

The length of MessageGroupId is 128 characters. Valid values: alphanumeric characters and punctuation (!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~).

For best practices of using MessageGroupId, see Using the MessageGroupId Property in the Amazon SQS Developer Guide.

MessageGroupId is required for FIFO queues. You can't use it for Standard queues.

Public Property MessageSystemAttributes System.Collections.Generic.Dictionary<System.String, Amazon.SQS.Model.MessageSystemAttributeValue>

Gets and sets the property MessageSystemAttributes.

The message system attribute to send. Each message system attribute consists of a Name, Type, and Value.

  • Currently, the only supported message system attribute is AWSTraceHeader. Its type must be String and its value must be a correctly formatted X-Ray trace header string.

  • The size of a message system attribute doesn't count towards the total size of a message.

Public Property QueueUrl System.String

Gets and sets the property QueueUrl.

The URL of the Amazon SQS queue to which a message is sent.

Queue URLs and names are case-sensitive.

Examples

This example shows how to send a message.

Send message example

var client = new AmazonSQSClient();

var request = new SendMessageRequest
{
  DelaySeconds = (int)TimeSpan.FromSeconds(5).TotalSeconds,
  MessageAttributes = new Dictionary<string, MessageAttributeValue>
  {
    {
      "MyNameAttribute", new MessageAttributeValue 
        { DataType = "String", StringValue = "John Doe" }
    },
    {
      "MyAddressAttribute", new MessageAttributeValue 
        { DataType = "String", StringValue = "123 Main St." }
    },
    {
      "MyRegionAttribute", new MessageAttributeValue 
        { DataType = "String", StringValue = "Any Town, United States" }
    }
  },
  MessageBody = "John Doe customer information.",
  QueueUrl = "https://sqs.us-east-1.amazonaws.com/80398EXAMPLE/MyTestQueue"
};

var response = client.SendMessage(request);

Console.WriteLine("For message ID '" + response.MessageId + "':");
Console.WriteLine("  MD5 of message attributes: " +
  response.MD5OfMessageAttributes);
Console.WriteLine("  MD5 of message body: " + response.MD5OfMessageBody);
      

Version Information

.NET Core App:
Supported in: 3.1

.NET Standard:
Supported in: 2.0

.NET Framework:
Supported in: 4.5, 4.0, 3.5