PopupControlContainer

Hi Michael,

You can use the SendKeys.Send method to send key message to child control. Below are the codes:

Control c = this.comboDropDown1.PopupContainer.Controls[0];
c.KeyPress += new KeyPressEventHandler(c_KeyPress);

//You need to set the focus to the control befor sending the key message.
c.Focus();
SendKeys.Send("{A}");

Best regards,
Haneef