Question

I’ve got a combobox that opens a new form window with a datagridview, and I want the users to choose the items through that datagridview rather than through the combobox. I’ve got this code to achieve that:

    private void comboBox1_DropDown(object sender, EventArgs e)
    {
        valSel.incBox = (ComboBox)sender;            
        valSel.Show();
        if (this.comboBox1.DroppedDown)
        {
            MessageBox.Show("test");
            SendMessage(this.comboBox1.Handle, CB_SHOWDROPDOWN, 0, 0);
        }
    }

As you see I’m also trying to hide the dropdown of the combobox but it isn’t working. I assume it’s because the combobox hasn’t actually “dropped down” yet, so that part of the code is never run.
Is there an event or something I can cell when the combobox has fully “dropped down” so i can send the message to close it again?

Answer 1

You should be able to simply set the height of the ComboBox to something really small. Last time I looked at it, this determined the height of the popup part (the actual height of the control is determined by the UI/font size).

The more elegant way, however, would be using a custom control that just mimics the appearance of dropdown boxes (I’m rather sure that can be done some easy way).