SqlCeDataReader.GetChars Method

Article
03/29/2011

Reads a stream of characters from the specified column offset into the buffer as an array starting at the given buffer offset.

Namespace: System.Data.SqlServerCe
Assembly: System.Data.SqlServerCe (in System.Data.SqlServerCe.dll)

Syntax

'Declaration
<SecurityTreatAsSafeAttribute> _
<SecurityCriticalAttribute> _
Public Overrides Function GetChars ( _
    ordinal As Integer, _
    dataIndex As Long, _
    buffer As Char(), _
    bufferIndex As Integer, _
    length As Integer _
) As Long
'Usage
Dim instance As SqlCeDataReader
Dim ordinal As Integer
Dim dataIndex As Long
Dim buffer As Char()
Dim bufferIndex As Integer
Dim length As Integer
Dim returnValue As Long

returnValue = instance.GetChars(ordinal, _
    dataIndex, buffer, bufferIndex, length)

[SecurityTreatAsSafeAttribute]
[SecurityCriticalAttribute]
public override long GetChars(
    int ordinal,
    long dataIndex,
    char[] buffer,
    int bufferIndex,
    int length
)

[SecurityTreatAsSafeAttribute]
[SecurityCriticalAttribute]
public:
virtual long long GetChars(
    int ordinal, 
    long long dataIndex, 
    array<wchar_t>^ buffer, 
    int bufferIndex, 
    int length
) override

[<SecurityTreatAsSafeAttribute>]
[<SecurityCriticalAttribute>]
abstract GetChars : 
        ordinal:int * 
        dataIndex:int64 * 
        buffer:char[] * 
        bufferIndex:int * 
        length:int -> int64 
[<SecurityTreatAsSafeAttribute>]
[<SecurityCriticalAttribute>]
override GetChars : 
        ordinal:int * 
        dataIndex:int64 * 
        buffer:char[] * 
        bufferIndex:int * 
        length:int -> int64

public override function GetChars(
    ordinal : int, 
    dataIndex : long, 
    buffer : char[], 
    bufferIndex : int, 
    length : int
) : long

Parameters

ordinal
Type: System.Int32
The zero-based column ordinal.

dataIndex
Type: System.Int64
The index within the row from which to begin the read operation.

buffer
Type: array<System.Char[]
The buffer into which to copy data.

bufferIndex
Type: System.Int32
The index for buffer to begin the read operation.

length
Type: System.Int32
The number of characters to read.

Return Value

Type: System.Int64
The actual number of characters read.

Implements

IDataRecord.GetChars(Int32, Int64, array<Char[], Int32, Int32)

Exceptions

Exception	Condition
InvalidOperationException	The operation is not valid. The SqlCeDataReader may be positioned after the last row in the result set.

Remarks

GetChars returns the number of available characters in the field. In most cases, this is the exact length of the field. However, the number returned may be less than the true length of the field if GetChars has already been used to obtain characters from the field. This may be the case, for example, when the SqlCeDataReader is reading a large data structure into a buffer. For more information, see the SequentialAccess setting for CommandBehavior.

If you pass a buffer that is nulla null reference (Nothing in Visual Basic), GetChars returns the length of the field in characters.

No conversions are performed; therefore, the data retrieved must already be a character array.