DataReader.IsNullItem Method (Int32)

Artikel
02/28/2011

Indicates whether the data item at the specified index is unspecified, that is, nulla null reference (Nothing in Visual Basic).

Namespace: Microsoft.VisualStudio.Data.Framework
Assembly: Microsoft.VisualStudio.Data.Framework (in Microsoft.VisualStudio.Data.Framework.dll)

Syntax

'Declaration
Public MustOverride Function IsNullItem ( _
    index As Integer _
) As Boolean

public abstract bool IsNullItem(
    int index
)

public:
virtual bool IsNullItem(
    int index
) abstract

abstract IsNullItem : 
        index:int -> bool

public abstract function IsNullItem(
    index : int
) : boolean

Parameters

index
Type: System.Int32
Index of the data item to examine.

Return Value

Type: System.Boolean
true if the item is nulla null reference (Nothing in Visual Basic), that is, unspecified; otherwise, false.

Implements

IVsDataReader.IsNullItem(Int32)

Remarks

Calling this method to figure out whether a value is nulla null reference (Nothing in Visual Basic) provides better performance than retrieving the value to see whether it is equal to Value, because the latter causes the entire value to be read from the data reader instance.

Notes to Inheritors

The derived class must override this method.

.NET Framework Security

Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.

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