Merlin's Delphi Forge

When creating forms with a lot of data entry you may want to consider the option to let the user focus the next edit control by hitting the Enter key. The default key is Tab which can become annoying
All we have to do is add the following code the each TEdit control on the form. You can do so by holding down the shift key and selecting each control. Then click the ObjectInspector and double click on OnKeyPress to create a shared event for all the controls. Then enter this code in the event procedure:

  ...
  uses
    Windows;
  ...
  if Key = #13 then begin
    { Make Windows focus the next edit control }
    Perform(WM_NEXTDLGCLTL, 0, 0);
    { Eat the enter key }
    Key := #0;
  end;
  ...

This code will work only with the controls that use this OnKeyPress event.
If you want all the edit controls on the form to act this way use a different way. This code does not require each edit control to use the above routine. Just the form’s KeyPreview property to True. Now add this code to the form’s KeyUp event and your all set If, for some reason you want to exclude any edit control from using Enter key instead to pass the focus all you have to do is modify the if condition to exclude certain edits. Instead of using there names you may want to consider the Tag property for this.

  ...
  if (Key = VK_RETURN) and ([ssCtrl, ssShift] * Shift = []) then
    Perform(WM_NEXTDLGCTL, 0, 0);
  ...

Note: Tip #42 refers to this topic too.

Delphi sends messages for notification of events that are only applicable to Delphi components. They are like Windows messages in use. If you have a component that publishes the Font property the component probably needs to be repainted if any subproperties in the Font are changed. Changing the Font property does not necessarily generate a Windows event but the control still needs to know about the change. Component messages serve this purpose.

This is a complete listing of the component messages and what they do. They are all defined in the controls.pas unit. This is a list of Delphi 5 component messages. The messages marked Notification Only do not pass any useful information to the message handler and do not expect the message handler to return a value. The messages on which I could not find information about I marked with a question mark “?”.

If you have any information about component messages and they are not listed here let me know, so as I can update this table. m3rlin@delphifaq.net