get datagridview cell value on first index changing

Question

I have a datagridview (dgv) and set some shortcut for it. I want to get my desired cell value when dgv selectedIndexChanged . this is what I've done for selectedIndexChanged event:

if (dgv.Rows.Count > 0)
{
      lblId.Text = dgv.CurrentRow.Cells[0].Value.ToString();
      lblStaffName.Text = dgv.CurrentRow.Cells[1].Value.ToString();
      lblStock.Text = dgv.CurrentRow.Cells[4].Value.ToString();  
}

and defined some shortcut for my dgv.

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
  if (keyData == (Keys.Alt | Keys.Down))
   {
      if (dgv.Rows.Count > 0)
       {
          dgv.Focus();
          if (dgv.CurrentRow.Index < (dgv.Rows.Count - 1))
            {
                dgv.Rows[dgv.CurrentRow.Index + 1].Selected = true;
                dgv.FirstDisplayedScrollingRowIndex = dgv.CurrentRow.Index + 1;
                pnl.BackColor = Color.FromKnownColor(KnownColor.Lime);
            }
        }
     }
}

NOTE: as you can see, when I press Alt+keyDown dgv index will increase and change to one step more.
My problem is when I pressed Alt+keyDown the index change and selected as well but the value won't get new value until I press again Alt+keyDown twice!
Is there any event that I must writing code in there? thanks :)

Reza Aghaei Reza Aghaei · Accepted Answer · 2016-11-26T00:17:34

To change the selected index in a data-bound DataGridView it's better to rely on the binding context this way:

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    if (keyData == (Keys.Alt | Keys.Down))
    {
        var bc = dgv.BindingContext[dgv.DataSource, dgv.DataMember];
        if (bc.Position < bc.Count - 1)
            bc.Position++;
        return true;
    }
    return base.ProcessCmdKey(ref msg, keyData);
}

But if the DataGridView is not data-bound or just for learning purpose you want to fix your code, you can write such code:

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    if (keyData == (Keys.Alt | Keys.Down))
    {
        if (dgv.CurrentCell == null)
        {
            if (dgv.ColumnCount >= 1 && dgv.RowCount >= 1)
            {
                dgv.CurrentCell = dgv[0, 0];
                return true;
            }
        }
        else
        {
            var rowIndex = dgv.CurrentCell.RowIndex;
            var columnIndex = dgv.CurrentCell.ColumnIndex;
            if (rowIndex < dgv.RowCount - 1)
            {
                dgv.CurrentCell = dgv[columnIndex, rowIndex + 1];
                return true;
            }
        }
    }
    return base.ProcessCmdKey(ref msg, keyData);
}

I also removed dgv.Focus() because when you use shortcuts to navigate between rows, you don't need focus, but if you need it for any reason, use it.

get datagridview cell value on first index changing

1 Answers