UnmanagedMemoryStream.ReadAsync Method

Definition

Namespace:

System.IO

Assembly:

System.Runtime.dll

Overloads

ReadAsync(Memory<Byte>, CancellationToken)	Asynchronously reads the unmanaged memory stream bytes into the memory region.
ReadAsync(Byte[], Int32, Int32, CancellationToken)	Asynchronously reads the specified number of bytes into the specified array.

ReadAsync(Memory<Byte>, CancellationToken)

Source:

UnmanagedMemoryStream.cs

Asynchronously reads the unmanaged memory stream bytes into the memory region.

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>

Public Overrides Function ReadAsync (buffer As Memory(Of Byte), Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of Integer)

Parameters

buffer

Memory<Byte>

When the asynchronous method finishes, this memory region contains all the bytes read from the unmanaged memory stream.

cancellationToken

CancellationToken

The token to monitor for cancellation requests. The default value is None.

Returns

ValueTask<Int32>

A task that represents the asynchronous read operation, and wraps the total number of bytes read into the buffer.

Exceptions

OperationCanceledException

The cancellation token was canceled. This exception is stored into the returned task.

ReadAsync(Byte[], Int32, Int32, CancellationToken)

Source:

UnmanagedMemoryStream.cs

Asynchronously reads the specified number of bytes into the specified array.

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);

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

Task<Int32>

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.

Exceptions

OperationCanceledException

The cancellation token was canceled. This exception is stored into the returned task.

Remarks

If an exception occurs during the read operation, it will be set as the Task.Exception of the property of the returned task.

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).