问设置网格的DataSource属性后，将未绑定列添加到数据视图中？

EN

DataTable tblTest = new DataTable(); //SELECT * FROM YourTable

//Calculate sum of population
Decimal overall = tblTest.AsEnumerable().Select(dr => dr.Field<Decimal>("Population")).DefaultIfEmpty().Sum();

tblTest.Columns.Add("Percentage", typeof(Decimal));
foreach(DataRow drow in tblTest.Rows)
{
    Decimal percentage = YourPercentageCalculationResult; //Add you calculation

    drow.SetField<Decimal>("Percentage", percentage);
}

//Create column "on runtime"
DataGridViewTextBoxColumn temp = New DataGridViewTextBoxColumn();
temp.DataPropertyName = "Percentage"
temp.ReadOnly = true;
grid.Columns.Add(temp);

grid.DataSource = tblTest;