แก้ไข

แชร์ผ่าน


NetworkStream.ReadAsync Method

Definition

Overloads

ReadAsync(Memory<Byte>, CancellationToken)

Reads data from the NetworkStream and stores it in a byte memory range as an asynchronous operation.

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

Reads data from the NetworkStream and stores it to a specified range of a byte array as an asynchronous operation.

ReadAsync(Memory<Byte>, CancellationToken)

Source:
NetworkStream.cs
Source:
NetworkStream.cs
Source:
NetworkStream.cs

Reads data from the NetworkStream and stores it in a byte memory range as an asynchronous operation.

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>

The buffer to write the data to.

cancellationToken
CancellationToken

The token to monitor for cancellation requests.

Returns

A ValueTask<TResult> that represents the asynchronous read operation. The value of its Result property contains the total number of bytes read into buffer.

Exceptions

The NetworkStream does not support reading.

An error occurred when accessing the socket.

-or-

There is a failure reading from the network.

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

Remarks

This method reads as much data as is available into buffer and returns the number of bytes successfully read.

Note

Check to see if the NetworkStream is readable by calling the CanRead property. If you attempt to read from a NetworkStream that is not readable, you will get an InvalidOperationException.

Note

If you receive an IOException, check the InnerException property to determine if it was caused by a SocketException. If so, use the ErrorCode property to obtain the specific error code and refer to the Windows Sockets version 2 API error code documentation for a detailed description of the error.

Applies to

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

Source:
NetworkStream.cs
Source:
NetworkStream.cs
Source:
NetworkStream.cs

Reads data from the NetworkStream and stores it to a specified range of a byte array as an asynchronous operation.

public:
 override System::Threading::Tasks::Task<int> ^ ReadAsync(cli::array <System::Byte> ^ buffer, int offset, int size, System::Threading::CancellationToken cancellationToken);
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 size, 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>
override this.ReadAsync : byte[] * int * int * System.Threading.CancellationToken -> System.Threading.Tasks.Task<int>
Public Overrides Function ReadAsync (buffer As Byte(), offset As Integer, size As Integer, cancellationToken As CancellationToken) As Task(Of Integer)
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 location in buffer to begin storing the data to.

sizecount
Int32

The number of bytes to read from the NetworkStream.

cancellationToken
CancellationToken

The token to monitor for cancellation requests.

Returns

A task that represents the asynchronous read operation. The value of its Result property contains the total number of bytes read into buffer.

Exceptions

The NetworkStream does not support reading.

An error occurred when accessing the socket.

-or-

There is a failure reading from the network.

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

Remarks

This method reads data into buffer and returns the number of bytes successfully read. The ReadAsync operation reads as much data as is available, up to the number of bytes specified by the size parameter.

Note

Check to see if the NetworkStream is readable by calling the CanRead property. If you attempt to read from a NetworkStream that is not readable, you will get an InvalidOperationException.

Note

If you receive an IOException, check the InnerException property to determine if it was caused by a SocketException. If so, use the ErrorCode property to obtain the specific error code and refer to the Windows Sockets version 2 API error code documentation for a detailed description of the error.

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).

Applies to