Apply Formula Cell to a DataGridview

Question

I want to add formula cell in a DataGridView. Is there any custom DataGridView to do this?

Example:

grid[4, column].Text =         


        

Answer 1

Is there any custom DataGridView to do this?

Off-topic, but if you are looking for a custom control, take a look at Free .NET Spreadsheet Control. Also it supports formula.

If writing code for calculation is an option for you

If writing code for calculation is an option for you, to calculate value of a cell based on values of some other cells you can use CellFormatting event of DataGridView and put calculation logic there. Also handle CellEndEdit and call InvalidateCell or Invalidate to force update value of cell after each in reference cells.

Here is an example:

void Form1_Load(object sender, EventArgs e)
{
    Random r = new Random();
    var dt = new DataTable();
    dt.Columns.Add("A", typeof(int));
    dt.Columns.Add("B", typeof(int));
    for (int i = 0; i < 10; i++)
        dt.Rows.Add(r.Next(100));
    grid.DataSource = dt;
    grid.CellFormatting += grid_CellFormatting;
    grid.CellEndEdit += grid_CellEndEdit;
}
void grid_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
    grid.Invalidate();
}
void grid_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
    var grid = sender as DataGridView;
    var parameterColumnName = "A";       //Parameter column name
    var start = 0;                       //Start row index for formula
    var end = grid.RowCount - 1;         //End row index for formula
    var resultRowIndex = 0;              //Result row index
    var resultColumnName = "B";          //Result column name
    if (e.RowIndex == resultRowIndex &&
        grid.Columns[e.ColumnIndex].Name == resultColumnName)
    {
        var list = Enumerable.Range(start, end - start + 1)
              .Select(i => grid.Rows[i].Cells[parameterColumnName].Value)
              .Where(x => x != null && x != DBNull.Value)
              .Cast();
        if (list.Any())
            e.Value = list.Max();
    }
}

Note

The solution is not limited to DataTable, it will work regardless of the DataSource which you use for DataGridView and you can use any kind of data source in this solution.