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DataColumnCollection.CanRemove Method

Checks whether a specific column can be removed from the collection.

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

'Declaration
Public Function CanRemove ( _
	column As DataColumn _
) As Boolean

Parameters

column
Type: System.Data.DataColumn

A DataColumn in the collection.

Return Value

Type: System.Boolean
true if the column can be removed. false if,
  • The column parameter is Nothing.

  • The column does not belong to this collection.

  • The column is part of a relationship.

  • Another column's expression depends on this column.

The CanRemove method performs several checks before returning a true or false result. This includes the following: whether the column exists, belongs to the table, or is involved in a constraint or relation.

Use the CanRemove method before you try to remove any column from a collection. You can also use the Contains method to determine whether a particular column exists before you try to remove it.

The following example first uses the Contains method to determine whether a particular column is found in the collection. If found, the CanRemove method tests whether the column can be removed. If so, the column is removed with the Remove method.

Private Sub RemoveColumn( _
    columnName As String, table As DataTable)

    Dim columns As DataColumnCollection = table.Columns
    If columns.Contains(columnName) Then  
        If columns.CanRemove(columns(columnName)) Then 
           columns.Remove(columnName)
        End If 
    End If 
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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