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DataRow.IsNull Method (String)

Gets a value that indicates whether the named column contains a null value.

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

'Declaration
Public Function IsNull ( _
	columnName As String _
) As Boolean

Parameters

columnName
Type: System.String

The name of the column.

Return Value

Type: System.Boolean
true if the column contains a null value; otherwise, false.

The following example changes the value of a column to a null value, and then uses the IsNull method to determine whether the value is null.

 Private Sub IsValNull()
    ' Assuming the DataGrid is bound to a DataTable. 
    Dim table As DataTable = CType(DataGrid1.DataSource, DataTable)
    Dim row As DataRow = table.Rows(datagrid1.CurrentCell.RowNumber)
    row.BeginEdit
    row("FirstName") = System.DBNull.Value
    row.EndEdit
    row.AcceptChanges
    Console.WriteLine(row.IsNull("FirstName"))
End Sub

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0
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