MemoryStream.ReadAsync Method
Definition
Important
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Overloads
| ReadAsync(Memory<Byte>, CancellationToken) |
Asynchronously reads a sequence of bytes from the current memory stream, writes the sequence into |
| ReadAsync(Byte[], Int32, Int32, CancellationToken) |
Asynchronously reads a sequence of bytes from the current stream, advances the position within the stream by the number of bytes read, and monitors cancellation requests. |
ReadAsync(Memory<Byte>, CancellationToken)
- Source:
- MemoryStream.cs
- Source:
- MemoryStream.cs
- Source:
- MemoryStream.cs
Asynchronously reads a sequence of bytes from the current memory stream, writes the sequence into destination, advances the position within the memory stream by the number of bytes read, and monitors cancellation requests.
public override System.Threading.Tasks.ValueTask<int> ReadAsync (Memory<byte> destination, System.Threading.CancellationToken cancellationToken = default);public override System.Threading.Tasks.ValueTask<int> ReadAsync (Memory<byte> buffer, System.Threading.CancellationToken cancellationToken = default);override this.ReadAsync : Memory<byte> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<int>override this.ReadAsync : Memory<byte> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<int>Public Overrides Function ReadAsync (destination As Memory(Of Byte), Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of Integer)Public Overrides Function ReadAsync (buffer As Memory(Of Byte), Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of Integer)Parameters
- cancellationToken
- CancellationToken
The token to monitor for cancellation requests. The default value is None.
Returns
A task that represents the asynchronous read operation. The value of its Result property contains the total number of bytes read into the destination. The result value can be less than the number of bytes allocated in destination if that many bytes are not currently available, or it can be 0 (zero) if the end of the memory stream has been reached.
Exceptions
The cancellation token was canceled. This exception is stored into the returned task.
Applies to
ReadAsync(Byte[], Int32, Int32, CancellationToken)
- Source:
- MemoryStream.cs
- Source:
- MemoryStream.cs
- Source:
- MemoryStream.cs
Asynchronously reads a sequence of bytes from the current stream, advances the position within the stream by the number of bytes read, and monitors cancellation requests.
public:
override System::Threading::Tasks::Task<int> ^ ReadAsync(cli::array <System::Byte> ^ buffer, int offset, int count, System::Threading::CancellationToken cancellationToken);public override System.Threading.Tasks.Task<int> ReadAsync (byte[] buffer, int offset, int count, System.Threading.CancellationToken cancellationToken);[System.Runtime.InteropServices.ComVisible(false)]
public override System.Threading.Tasks.Task<int> ReadAsync (byte[] buffer, int offset, int count, System.Threading.CancellationToken cancellationToken);override this.ReadAsync : byte[] * int * int * System.Threading.CancellationToken -> System.Threading.Tasks.Task<int>[<System.Runtime.InteropServices.ComVisible(false)>]
override this.ReadAsync : byte[] * int * int * System.Threading.CancellationToken -> System.Threading.Tasks.Task<int>Public Overrides Function ReadAsync (buffer As Byte(), offset As Integer, count As Integer, cancellationToken As CancellationToken) As Task(Of Integer)Parameters
- buffer
- Byte[]
The buffer to write the data into.
- offset
- Int32
The byte offset in buffer at which to begin writing data from the stream.
- count
- Int32
The maximum number of bytes to read.
- cancellationToken
- CancellationToken
The token to monitor for cancellation requests. The default value is None.
Returns
A task that represents the asynchronous read operation. The value of the TResult parameter contains the total number of bytes read into the buffer. The result value can be less than the number of bytes requested if the number of bytes currently available is less than the requested number, or it can be 0 (zero) if the end of the stream has been reached.
- Attributes
Exceptions
buffer is null.
offset or count is negative.
The sum of offset and count is larger than the buffer length.
The stream does not support reading.
The stream has been disposed.
The stream is currently in use by a previous read operation.
The cancellation token was canceled. This exception is stored into the returned task.
Remarks
If the operation is canceled before it completes, the returned task contains the Canceled value for the Status property.
You can create a cancellation token by creating an instance of the CancellationTokenSource class and passing the Token property as the cancellationToken parameter.
This method stores in the task it returns all non-usage exceptions that the method's synchronous counterpart can throw. If an exception is stored into the returned task, that exception will be thrown when the task is awaited. Usage exceptions, such as ArgumentException, are still thrown synchronously. For the stored exceptions, see the exceptions thrown by Read(Byte[], Int32, Int32).
