Datagridview custom row highlight - winforms

Question

I have a DataGridView (WinForms, C#). All I wanted to do is to divide grid on left/ right parts. So, when I click on left part (3,3) will highlights for example, when click on right part (6,6) will be highlighted.
Col1 | Col2 | Col3 | Col4
-------------------------
1 1 2 2
3 3 4 4
5 5 6 6
Getting the value not a problem, but highlights.. ?
int iCol = dgv.CurrentCell.ColumnIndex;
if (iCol == 0 || iCol == 1) // left side
{
}
else // right side
{
}

Answer 1

I hope this helps you, but you should not write column indexes directly in code, I think coltroling indexes with mathematical expression is better solution.
Also this code would be slow with big data, so that you can use column select. But if you use column select, it would prevent reordering rows when you clicked column header.
Private Sub DataGridView1_CellClick(sender As System.Object, e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellClick
DataGridView1.SelectionMode = DataGridViewSelectionMode.CellSelect
If e.ColumnIndex < DataGridView1.ColumnCount / 2 Then
For Each c As DataGridViewColumn In DataGridView1.Columns
If c.Index < DataGridView1.ColumnCount / 2 Then
For Each r As DataGridViewRow In DataGridView1.Rows
r.Cells(c.Index).Style.BackColor = Color.Blue
Next
Else
For Each r As DataGridViewRow In DataGridView1.Rows
r.Cells(c.Index).Style.BackColor = Color.Gray
Next
End If
Next
Else
For Each c As DataGridViewColumn In DataGridView1.Columns
If c.Index >= DataGridView1.ColumnCount / 2 Then
For Each r As DataGridViewRow In DataGridView1.Rows
r.Cells(c.Index).Style.BackColor = Color.Blue
Next
Else
For Each r As DataGridViewRow In DataGridView1.Rows
r.Cells(c.Index).Style.BackColor = Color.Gray
Next
End If
Next
End If
End Sub