CryptoStream.WriteAsync(Byte[], Int32, Int32, CancellationToken) 方法

定义

将字节序列异步写入当前流,将该流的当前位置向前移动写入的字节数,并监视取消请求。Writes a sequence of bytes to the current stream asynchronously, advances the current position within the stream by the number of bytes written, and monitors cancellation requests.

public:
 override System::Threading::Tasks::Task ^ WriteAsync(cli::array <System::Byte> ^ buffer, int offset, int count, System::Threading::CancellationToken cancellationToken);
public override System.Threading.Tasks.Task WriteAsync (byte[] buffer, int offset, int count, System.Threading.CancellationToken cancellationToken);
override this.WriteAsync : byte[] * int * int * System.Threading.CancellationToken -> System.Threading.Tasks.Task

参数

buffer
Byte[]

要从中写入数据的缓冲区。The buffer to write data from.

offset
Int32

buffer 中的从零开始的字节偏移量,从此处开始将字节写入到该流。The zero-based byte offset in buffer from which to begin writing bytes to the stream.

count
Int32

要写入的最大字节数。The maximum number of bytes to write.

cancellationToken
CancellationToken

要监视的取消请求标记。The token to monitor for cancellation requests. 默认值为 NoneThe default value is None.

返回

表示异步写入操作的任务。A task that represents the asynchronous write operation.

异常

buffernullbuffer is null.

offsetcount 为负数。offset or count is negative.

offsetcount 的总和大于缓冲区长度。The sum of offset and count is larger than the buffer length.

流不支持写入。The stream does not support writing.

已释放流。The stream has been disposed.

流正在由前一次写操作使用。The stream is currently in use by a previous write operation.

注解

必须先将对的调用 WriteAsyncawait (C#)或 Await (Visual Basic)运算符,才能暂停执行方法,直到任务完成。You must preface your call to WriteAsync with the await (C#) or Await (Visual Basic) operator to suspend execution of the method until the task is complete. 有关详细信息,请参阅使用 Async 和 Await 的异步编程For more information, see Asynchronous Programming with Async and Await.

如果在操作完成前取消该操作,则返回的任务将包含 Status 属性的 Canceled 值。If the operation is canceled before it completes, the returned task contains the Canceled value for the Status property.

适用于

另请参阅