从数据表C＃中删除列

Question

我目前正在将字段从上传的Excel文档映射到数据表。我希望未选择的列被删除，但它们仍然显示。

这是我的代码：

if(DT.Columns.IndexOf("First Name") != -1)
                DT.Columns["First Name"].ColumnName = "First NameMap";
            DT.Columns[mapping.FirstNameColumnId].ColumnName = "First Name";

            if (DT.Columns.IndexOf("Last Name") != -1)
                DT.Columns["Last Name"].ColumnName = "Last NameMap";
            DT.Columns[mapping.LastNameColumnId].ColumnName = "Last Name";

            if (DT.Columns.IndexOf("Email Address") != -1)
                DT.Columns["Email Address"].ColumnName = "Email AddressMap";
            DT.Columns[mapping.EmailColumnId].ColumnName = "Email Address";


            int ColumnCounter = 0;
            foreach(DataColumn column in DT.Columns)
            {
                if(ColumnCounter != mapping.FirstNameColumnId && ColumnCounter != mapping.LastNameColumnId && ColumnCounter != mapping.EmailColumnId)
                {
                    DT.Columns.Remove(column);
                }
            }

Answer 1

   DataTable t;
   t.Columns.Remove("columnName");
   t.Columns.RemoveAt(columnIndex);