https://learn.microsoft.com/ja-jp/dotnet/api/system.data.datatable.onremovecolumn?view=netframework-4.8.1&viewFallbackFrom=net-10.0
DataTable.OnRemoveColumn(DataColumn) Method (System.Data) | Microsoft Learn
Notifies the DataTable that a DataColumn is being removed.
system datadatatabledatacolumnmethodmicrosoft