sum of manually selected rows of datagridview

Hi all,

I have a datagridview on my desktop application, what I need is to show in a a textbox the sum of collums values, of rows selected manually. Is this possible??????
Can you guys help me on this?

which columnIndex contains the numeric value?

try this (uses column 0):

vb Code:

Private Sub DataGridView1_SelectionChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DataGridView1.SelectionChanged
    TextBox1.Text = (From row As DataGridViewRow In DataGridView1.Rows.Cast(Of DataGridViewRow)() _
                     Where row.Selected = True _
                     Select CInt(row.Cells(0).Value)).Sum.ToString
End Sub

The DataTable.Compute Method might help.

Very good guys, it worked very well, thanks a lot.