[rmnr]

كود :

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
   Dim total As Double = 0
   For Each r As DataGridViewRow In Me.DataGridView1.Rows
       If r.IsNewRow Then Exit For
       If r.Cells(0).Value.ToString = "خالد" Then
           total += Val(r.Cells(1).Value)
       End If
   Next
   TextBox1.Text = total
End Sub