SqlCommand::ExecuteReaderAsync Method (CommandBehavior, CancellationToken)
An asynchronous version of ExecuteReader, which sends the CommandText to the Connection, and builds a SqlDataReader
The cancellation token can be used to request that the operation be abandoned before the command timeout elapses. Exceptions will be reported via the returned Task object.
Assembly: System.Data (in System.Data.dll)
public:
Task<SqlDataReader^>^ ExecuteReaderAsync(
CommandBehavior behavior,
CancellationToken cancellationToken
)
Parameters
- behavior
-
Type:
System.Data::CommandBehavior
Options for statement execution and data retrieval. When is set to Default, ReadAsync reads the entire row before returning a complete Task.
- cancellationToken
-
Type:
System.Threading::CancellationToken
The cancellation instruction.
Return Value
Type: System.Threading.Tasks::Task<SqlDataReader^>^A task representing the asynchronous operation.
| Exception | Condition |
|---|---|
| InvalidCastException | A SqlDbType other than Binary or VarBinary was used when Value was set to Stream. For more information about streaming, see SqlClient Streaming Support. A SqlDbType other than Char, NChar, NVarChar, VarChar, or Xml was used when Value was set to TextReader. A SqlDbType other than Xml was used when Value was set to XmlReader. |
| ArgumentException | An invalid CommandBehavior value. |
| InvalidOperationException | Calling ExecuteReaderAsync more than once for the same instance before task completion. The SqlConnection closed or dropped during a streaming operation. For more information about streaming, see SqlClient Streaming Support. Context Connection=true is specified in the connection string. |
| SqlException | SQL Server returned an error while executing the command text. A timeout occurred during a streaming operation. For more information about streaming, see SqlClient Streaming Support. |
| IOException | An error occurred in a Stream, XmlReader or TextReader object during a streaming operation. For more information about streaming, see SqlClient Streaming Support. |
| ObjectDisposedException | The Stream, XmlReader or TextReader object was closed during a streaming operation. For more information about streaming, see SqlClient Streaming Support. |
For more information about asynchronous programming in the .NET Framework Data Provider for SQL Server, see Asynchronous Programming.
Available since 4.5