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SqlCeDataReader.GetChars Method

  • Artigo

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
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)

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

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

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

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

Not applicable.

Parameters

  • ordinal
    The zero-based column ordinal.
  • dataIndex
    The index within the row from which to begin the read operation.
  • buffer
    The buffer into which to copy data.
  • bufferIndex
    The index for buffer to begin the read operation.
  • length
    The number of characters to read.

Return Value

The actual number of characters read.

Exceptions

Exception type 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 a 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.

Platforms

Windows CE, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows XP Professional x64 Edition, Windows XP SP2

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

Version Information

.NET Framework

Supported in: 3.0

.NET Compact Framework

Supported in: 2.0, 1.0

See Also

Reference

SqlCeDataReader Class
SqlCeDataReader Members
System.Data.SqlServerCe Namespace