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.

The HEAD operation retrieves metadata from an object without returning the object itself. This operation is useful if you're only interested in an object's metadata. To use HEAD, you must have READ access to the object.

A HEAD request has the same options as a GET operation on an object. The response is identical to the GET response except that there is no response body.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you retrieve the metadata from the object, you must use the following headers:

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys).

Encryption request headers, like x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with CMKs stored in AWS KMS (SSE-KMS) or server-side encryption with Amazon S3–managed encryption keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 BadRequest error.

Request headers are limited to 8 KB in size. For more information, see Common Request Headers.

Consider the following when using request headers:

For more information about conditional requests, see RFC 7232.

Permissions

You need the s3:GetObject permission for this operation. For more information, see Specifying Permissions in a Policy. If the object you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

The following operation is related to HeadObject:

Note:

This is an asynchronous operation using the standard naming convention for .NET 4.5 or higher. For .NET 3.5 the operation is implemented as a pair of methods using the standard naming convention of BeginGetObjectMetadata and EndGetObjectMetadata. For Unity the operation does not take CancellationToken as a parameter, and instead takes AmazonServiceCallback<GetObjectMetadataRequest, GetObjectMetadataResponse> and AsyncOptions as additional parameters.

Namespace: Amazon.S3
Assembly: AWSSDK.S3.dll
Version: 3.x.y.z

Syntax

C#
public abstract Task<GetObjectMetadataResponse> GetObjectMetadataAsync(
         GetObjectMetadataRequest request,
         CancellationToken cancellationToken
)
Parameters
request
Type: Amazon.S3.Model.GetObjectMetadataRequest

Container for the necessary parameters to execute the GetObjectMetadata service method.

cancellationToken
Type: System.Threading.CancellationToken

A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Return Value
The response from the GetObjectMetadata service method, as returned by S3.

Version Information

.NET Standard:
Supported in: 2.0, 1.3

.NET Framework:
Supported in: 4.5

Portable Class Library:
Supported in: Windows Store Apps
Supported in: Xamarin Android
Supported in: Xamarin iOS (Unified)
Supported in: Xamarin.Forms

Unity:
Supported Versions: 4.6 and above
Supported Platforms: Android, iOS, Standalone

See Also