DataReader.IsNullItem Method (String)
Indicates whether the value of the given data item 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 Overridable Function IsNullItem ( _
name As String _
) As Boolean
public virtual bool IsNullItem(
string name
)
public:
virtual bool IsNullItem(
String^ name
)
abstract IsNullItem :
name:string -> bool
override IsNullItem :
name:string -> bool
public function IsNullItem(
name : String
) : boolean
Parameters
name
Type: System.StringThe name 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(String)
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.
This method calls GetItemIndex to get the index corresponding to the item name and then passes this index to IsNullItem to retrieve the requested number of bytes of raw binary data.
.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.