CloudBlob.BeginOpenRead Method
Definition
Important
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Overloads
| BeginOpenRead(AsyncCallback, Object) |
Begins an asynchronous operation to open a stream for reading from the blob. |
| BeginOpenRead(AccessCondition, BlobRequestOptions, OperationContext, AsyncCallback, Object) |
Begins an asynchronous operation to open a stream for reading from the blob. |
BeginOpenRead(AsyncCallback, Object)
Begins an asynchronous operation to open a stream for reading from the blob.
[Microsoft.Azure.Storage.DoesServiceRequest]
public virtual Microsoft.Azure.Storage.ICancellableAsyncResult BeginOpenRead (AsyncCallback callback, object state);[<Microsoft.Azure.Storage.DoesServiceRequest>]
abstract member BeginOpenRead : AsyncCallback * obj -> Microsoft.Azure.Storage.ICancellableAsyncResult
override this.BeginOpenRead : AsyncCallback * obj -> Microsoft.Azure.Storage.ICancellableAsyncResultPublic Overridable Function BeginOpenRead (callback As AsyncCallback, state As Object) As ICancellableAsyncResultParameters
- callback
- AsyncCallback
An AsyncCallback delegate that will receive notification when the asynchronous operation completes.
- state
- Object
A user-defined object that will be passed to the callback delegate.
Returns
An ICancellableAsyncResult that references the asynchronous operation.
- Attributes
Remarks
On the Stream object returned by the EndOpenRead(IAsyncResult) method, the EndRead(IAsyncResult) method must be called exactly once for every BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) call. Failing to end the read process before beginning another read process can cause unexpected behavior.
Note that this method always makes a call to the BeginFetchAttributes(AccessCondition, BlobRequestOptions, OperationContext, AsyncCallback, Object) method under the covers.
Set the StreamMinimumReadSizeInBytes property before calling this method to specify the minimum number of bytes to buffer when reading from the stream. The value must be at least 16 KB.
Applies to
BeginOpenRead(AccessCondition, BlobRequestOptions, OperationContext, AsyncCallback, Object)
Begins an asynchronous operation to open a stream for reading from the blob.
[Microsoft.Azure.Storage.DoesServiceRequest]
public virtual Microsoft.Azure.Storage.ICancellableAsyncResult BeginOpenRead (Microsoft.Azure.Storage.AccessCondition accessCondition, Microsoft.Azure.Storage.Blob.BlobRequestOptions options, Microsoft.Azure.Storage.OperationContext operationContext, AsyncCallback callback, object state);[<Microsoft.Azure.Storage.DoesServiceRequest>]
abstract member BeginOpenRead : Microsoft.Azure.Storage.AccessCondition * Microsoft.Azure.Storage.Blob.BlobRequestOptions * Microsoft.Azure.Storage.OperationContext * AsyncCallback * obj -> Microsoft.Azure.Storage.ICancellableAsyncResult
override this.BeginOpenRead : Microsoft.Azure.Storage.AccessCondition * Microsoft.Azure.Storage.Blob.BlobRequestOptions * Microsoft.Azure.Storage.OperationContext * AsyncCallback * obj -> Microsoft.Azure.Storage.ICancellableAsyncResultPublic Overridable Function BeginOpenRead (accessCondition As AccessCondition, options As BlobRequestOptions, operationContext As OperationContext, callback As AsyncCallback, state As Object) As ICancellableAsyncResultParameters
- accessCondition
- AccessCondition
An AccessCondition object that represents the condition that must be met in order for the request to proceed. If null, no condition is used.
- options
- BlobRequestOptions
A BlobRequestOptions object that specifies additional options for the request.
- operationContext
- OperationContext
An OperationContext object that represents the context for the current operation.
- callback
- AsyncCallback
An AsyncCallback delegate that will receive notification when the asynchronous operation completes.
- state
- Object
A user-defined object that will be passed to the callback delegate.
Returns
An ICancellableAsyncResult that references the asynchronous operation.
- Attributes
Remarks
On the Stream object returned by the EndOpenRead(IAsyncResult) method, the EndRead(IAsyncResult) method must be called exactly once for every BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) call. Failing to end the read process before beginning another read process can cause unexpected behavior.
Note that this method always makes a call to the BeginFetchAttributes(AccessCondition, BlobRequestOptions, OperationContext, AsyncCallback, Object) method under the covers.
Set the StreamMinimumReadSizeInBytes property before calling this method to specify the minimum number of bytes to buffer when reading from the stream. The value must be at least 16 KB.
Applies to
Azure SDK for .NET