Sample C# Code Using DreamObjects S3-compatible API

This article uses the new DreamObjects cluster of ''. If you have an older DreamObjects account and have not migrated your data yet, your hostname may need to point to '' instead. Please review the following migration article for further details.

This article lists several C# code examples to interact with DreamObjects.

Creating a Connection

Create a connection so you can interact with the server.

using System;
using Amazon;
using Amazon.S3;
using Amazon.S3.Model;

string accessKey = "put your access key here!";
string secretKey = "put your secret key here!";

AmazonS3Config config = new AmazonS3Config();
config.ServiceURL = "";

AmazonS3 client = Amazon.AWSClientFactory.CreateAmazonS3Client(

Listing Owned Buckets

Get a list of Buckets you own. This also prints out the bucket name and creation date of each bucket.

ListBucketResponse response = client.ListBuckets();
foreach (S3Bucket b in response.Buckets)
        Console.WriteLine("{0}\t{1}", b.BucketName, b.CreationDate);

The output will look something like this:

mahbuckat1   2011-04-21T18:05:39.000Z
mahbuckat2   2011-04-21T18:05:48.000Z
mahbuckat3   2011-04-21T18:07:18.000Z

Creating a Bucket

Create a new bucket called my-new-bucket.

PutBucketRequest request = new PutBucketRequest();
request.BucketName = "my-new-bucket";

Listing a Bucket’s Content

Get a list of objects in the bucket. This also prints out each object’s name, the file size, and last modified date.

ListObjectsRequest request = new ListObjectsRequest();
request.BucketName = "my-new-bucket";
ListObjectsResponse response = client.ListObjects(request);
foreach (S3Object o in response.S3Objects)
        Console.WriteLine("{0}\t{1}\t{2}", o.Key, o.Size, o.LastModified);

The output will look something like this:

myphoto1.jpg 251262  2011-08-08T21:35:48.000Z
myphoto2.jpg 262518  2011-08-08T21:38:01.000Z

Deleting a Bucket

The Bucket must be empty, otherwise it won’t work.

DeleteBucketRequest request = new DeleteBucketRequest();
request.BucketName = "my-new-bucket";

Forced Delete for Non-empty Buckets

not available

Creating an Object

Create a file hello.txt with the string "Hello World!"

PutObjectRequest request = new PutObjectRequest();
request.Bucket      = "my-new-bucket";
request.Key         = "hello.txt";
request.ContentType = "text/plain";
request.ContentBody = "Hello World!";

Change an Object’s ACL

Make the object hello.txt publicly readable and secret_plans.txt to be private.

SetACLRequest request = new SetACLRequest();
request.BucketName = "my-new-bucket";
request.Key        = "hello.txt";
request.CannedACL  = S3CannedACL.PublicRead;

SetACLRequest request2 = new SetACLRequest();
request2.BucketName = "my-new-bucket";
request2.Key        = "secret_plans.txt";
request2.CannedACL  = S3CannedACL.Private;

Download an Object (to a file)

Download the object perl_poetry.pdf and save it in C:\Users\larry\Documents.

GetObjectRequest request = new GetObjectRequest();
request.BucketName = "my-new-bucket";
request.Key        = "perl_poetry.pdf"
GetObjectResponse response = client.GetObject(request);

Delete an Object

Delete the object goodbye.txt.

DeleteObjectRequest request = new DeleteObjectRequest();
request.BucketName = "my-new-bucket";
request.Key        = "goodbye.txt";

Generate Object Download URLs (signed and unsigned)

This generates an unsigned download URL for hello.txt. This works because hello.txt was made public by setting the ACL above. This then generates a signed download URL for secret_plans.txt that will work for 1 hour. Signed download URLs will work for the time period even if the object is private (when the time period is up, the URL will stop working).

The C# S3 Library does not have a method for generating unsigned URLs, so the following example only shows generating signed URLs.

GetPreSignedUrlRequest request = new GetPreSignedUrlRequest();
request.BucketName = "my-bucket-name";
request.Key        = "secret_plans.txt";
request.Expires    = DateTime.Now.AddHours(1);
request.Protocol   = Protocol.HTTP;
string url = client.GetPreSignedURL(request);

The output of this will look something like:

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Article last updated PST.