SqlDataReader.GetFieldValueAsync(Int32, CancellationToken) SqlDataReader.GetFieldValueAsync(Int32, CancellationToken) SqlDataReader.GetFieldValueAsync(Int32, CancellationToken) Method

Definition

Asynchronously gets the value of the specified column as a type. GetFieldValue<T>(Int32) is the synchronous version of this method.

public:
generic <typename T>
 override System::Threading::Tasks::Task<T> ^ GetFieldValueAsync(int i, System::Threading::CancellationToken cancellationToken);
public override System.Threading.Tasks.Task<T> GetFieldValueAsync<T> (int i, System.Threading.CancellationToken cancellationToken);
override this.GetFieldValueAsync : int * System.Threading.CancellationToken -> System.Threading.Tasks.Task<'T>

Type Parameters

T

The type of the value to be returned.

Parameters

i
Int32 Int32 Int32

The column to be retrieved.

cancellationToken
CancellationToken CancellationToken CancellationToken

The cancellation instruction, which propagates a notification that operations should be canceled. This does not guarantee the cancellation. A setting of CancellationToken.None makes this method equivalent to IsDBNull(Int32). The returned task must be marked as cancelled.

Returns

Task<T>

The returned type object.

Exceptions

The connection drops or is closed during the data retrieval.

The SqlDataReader is closed during the data retrieval.

There is no data ready to be read (for example, the first Read() hasn't been called, or returned false).

Tried to read a previously-read column in sequential mode.

There was an asynchronous operation in progress. This applies to all Get* methods when running in sequential mode, as they could be called while reading a stream.

Context Connection=true is specified in the connection string.

Trying to read a column that does not exist.

The value of the column was null (IsDBNull(Int32) == true), retrieving a non-SQL type.

T doesn't match the type returned by SQL Server or cannot be cast.

Remarks

T can be one of the following types:

Boolean Byte Char DateTime
DateTimeOffset Decimal Double Float
Guid Int16 Int32 Int64
SqlBoolean SqlByte SqlDateTime SqlDecimal
SqlDouble SqlGuid SqlInt16 SqlInt32
SqlInt64 SqlMoney SqlSingle SqlString
String UDT, which can be any CLR type marked with SqlUserDefinedTypeAttribute.

For more information, see SqlClient Streaming Support.

Applies to