AWS SDK Version 3 for .NET
API Reference

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Container for the parameters to the InitiateMultipartUpload operation.

Initiates a multipart upload and returns an upload ID.

Inheritance Hierarchy


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


public class InitiateMultipartUploadRequest : PutWithACLRequest

The InitiateMultipartUploadRequest type exposes the following members



Public Property BucketName System.String

The name of the bucketName where the new object will be created, or existing object updated.

Public Property CannedACL Amazon.S3.S3CannedACL

A canned access control list (ACL) to apply to the object. Please refer to Amazon.S3.S3CannedACL for information on S3 Canned ACLs.

Public Property ContentType System.String

This is a convenience property for Headers.ContentType.

Public Property ExpectedBucketOwner System.String

The account id of the expected bucket owner. If the bucket is owned by a different account, the request will fail with an HTTP 403 (Access Denied) error.

Public Property Grants System.Collections.Generic.List<Amazon.S3.Model.S3Grant> Inherited from Amazon.S3.Model.PutWithACLRequest.
Public Property Headers Amazon.S3.Model.HeadersCollection

The collection of headers for the request.

Public Property Key System.String

The key of the object to create or update.

Public Property Metadata Amazon.S3.Model.MetadataCollection

The collection of meta data for the request.

Public Property ObjectLockLegalHoldStatus Amazon.S3.ObjectLockLegalHoldStatus

Gets and sets the property ObjectLockLegalHoldStatus.

Specifies whether you want to apply a Legal Hold to the uploaded object.

Public Property ObjectLockMode Amazon.S3.ObjectLockMode

Gets and sets the property ObjectLockMode.

Specifies the Object Lock mode that you want to apply to the uploaded object.

Public Property ObjectLockRetainUntilDate System.DateTime

Gets and sets the property ObjectLockRetainUntilDate.

Specifies the date and time when you want the Object Lock to expire.

Public Property RequestPayer Amazon.S3.RequestPayer

Confirms that the requester knows that she or he will be charged for the list objects request. Bucket owners need not specify this parameter in their requests.

Public Property ServerSideEncryptionCustomerMethod Amazon.S3.ServerSideEncryptionCustomerMethod

The Server-side encryption algorithm to be used with the customer provided key.

Public Property ServerSideEncryptionCustomerProvidedKey System.String

The base64-encoded encryption key for Amazon S3 to use to encrypt the object

Using the encryption key you provide as part of your request Amazon S3 manages both the encryption, as it writes to disks, and decryption, when you access your objects. Therefore, you don't need to maintain any data encryption code. The only thing you do is manage the encryption keys you provide.

When you retrieve an object, you must provide the same encryption key as part of your request. Amazon S3 first verifies the encryption key you provided matches, and then decrypts the object before returning the object data to you.

Important: Amazon S3 does not store the encryption key you provide.

Public Property ServerSideEncryptionCustomerProvidedKeyMD5 System.String

The MD5 of the customer encryption key specified in the ServerSideEncryptionCustomerProvidedKey property. The MD5 is base 64 encoded. This field is optional, the SDK will calculate the MD5 if this is not set.

Public Property ServerSideEncryptionKeyManagementServiceEncryptionContext System.String

Specifies the AWS KMS Encryption Context to use for object encryption. The value of this header is a base64-encoded UTF-8 string holding JSON with the encryption context key-value pairs.

Public Property ServerSideEncryptionKeyManagementServiceKeyId System.String

The id of the AWS Key Management Service key that Amazon S3 should use to encrypt and decrypt the object. If a key id is not specified, the default key will be used for encryption and decryption.

Public Property ServerSideEncryptionMethod Amazon.S3.ServerSideEncryptionMethod

Specifies the encryption to be used on the server for the new object.

Public Property StorageClass Amazon.S3.S3StorageClass

StorageClass property for the object.

Public Property TagSet System.Collections.Generic.List<Amazon.S3.Model.Tag>

The tag-set for the object. The tag-set must be encoded as URL Query parameters.

Public Property WebsiteRedirectLocation System.String

If the bucketName is configured as a website, redirects requests for this object to another object in the same bucketName or to an external URL. Amazon S3 stores the value of this header in the object metadata.


This example shows how to upload 13MB of data using mutlipart upload.
The data is contained in a stream and the upload is done in 3 parts: 5MB, 5MB, then the remainder.

Multipart Upload Sample

int MB = (int)Math.Pow(2, 20);

// Create a client
AmazonS3Client client = new AmazonS3Client();

// Define input stream
Stream inputStream = Create13MBDataStream();

// Initiate multipart upload
InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest
    BucketName = "SampleBucket",
    Key = "Item1"
InitiateMultipartUploadResponse initResponse = client.InitiateMultipartUpload(initRequest);

// Upload part 1
UploadPartRequest uploadRequest = new UploadPartRequest
    BucketName = "SampleBucket",
    Key = "Item1",
    UploadId = initResponse.UploadId,
    PartNumber = 1,
    PartSize = 5 * MB,
    InputStream = inputStream
UploadPartResponse up1Response = client.UploadPart(uploadRequest);

// Upload part 2
uploadRequest = new UploadPartRequest
    BucketName = "SampleBucket",
    Key = "Item1",
    UploadId = initResponse.UploadId,
    PartNumber = 2,
    PartSize = 5 * MB,
    InputStream = inputStream
UploadPartResponse up2Response = client.UploadPart(uploadRequest);

// Upload part 3
uploadRequest = new UploadPartRequest
    BucketName = "SampleBucket",
    Key = "Item1",
    UploadId = initResponse.UploadId,
    PartNumber = 3,
    InputStream = inputStream
UploadPartResponse up3Response = client.UploadPart(uploadRequest);

// List parts for current upload
ListPartsRequest listPartRequest = new ListPartsRequest
    BucketName = "SampleBucket",
    Key = "Item1",
    UploadId = initResponse.UploadId
ListPartsResponse listPartResponse = client.ListParts(listPartRequest);
Debug.Assert(listPartResponse.Parts.Count == 3);

// Complete the multipart upload
CompleteMultipartUploadRequest compRequest = new CompleteMultipartUploadRequest
    BucketName = "SampleBucket",
    Key = "Item1",
    UploadId = initResponse.UploadId,
    PartETags = new List<PartETag>
        new PartETag { ETag = up1Response.ETag, PartNumber = 1 },
        new PartETag { ETag = up2Response.ETag, PartNumber = 2 },
        new PartETag { ETag = up3Response.ETag, PartNumber = 3 }
CompleteMultipartUploadResponse compResponse = client.CompleteMultipartUpload(compRequest);


Version Information

.NET Core App:
Supported in: 3.1

.NET Standard:
Supported in: 2.0, 1.3

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