Public Overrides Function GetChars(
    ByVal ordinal As Integer,
    ByVal dataIndex As Long,
    ByVal buffer As Char(),
    ByVal bufferIndex As Integer,
    ByVal length As Integer
) As Long

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

The actual number of characters read.

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 SADataReader is reading a large data structure into a buffer.

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

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

For information about handling BLOBs, see Handling BLOBs.