Stream. Begin Read(Byte, Int32, Int32, AsyncCallback, Object) Method
Begins an asynchronous read operation. (Consider using ReadAsync(Byte, Int32, Int32, CancellationToken) instead.)
public: override IAsyncResult ^ BeginRead(cli::array <System::Byte> ^ buffer, int offset, int count, AsyncCallback ^ callback, System::Object ^ state);
public override IAsyncResult BeginRead (byte buffer, int offset, int count, AsyncCallback callback, object state);
override this.BeginRead : byte * int * int * AsyncCallback * obj -> IAsyncResult
Public Overrides Function BeginRead (buffer As Byte(), offset As Integer, count As Integer, callback As AsyncCallback, state As Object) As IAsyncResult
The buffer to read the data into.
The byte offset in
buffer at which to begin writing data read from the stream.
The maximum number of bytes to read.
An optional asynchronous callback, to be called when the read is complete.
A user-provided object that distinguishes this particular asynchronous read request from other requests.
An object that represents the asynchronous read, which could still be pending.
count is negative.
Attempted an asynchronous read past the end of the stream.
The buffer length minus
offset is less than
The current stream does not support the read operation.
In the .NET Framework 4 and earlier versions, you have to use methods such as BeginRead and EndRead to implement asynchronous file operations. These methods are still available in the .NET Framework 4.5 to support legacy code; however, the new async methods, such as ReadAsync, WriteAsync, and FlushAsync, help you implement asynchronous file operations more easily.
Use the CanRead property to determine whether the current instance supports reading.