Write Components which handle ENTER-Key like TAB-Key (Views: 2141)
Problem/Question/Abstract: Standard-behaviour of controls when pressing ENTER-KEY is a BEEP-Sound. But how to write Components which handle ENTER-Key like TAB-Key? Answer: This Article will show how to write Components which will handle the ENTER-Key in the same behaviour like the TAB-Key. As Sample I will take a TEdit-Component but it should work on oll other components with OnKeyPress-Event. Create a new Component from TEdit with a new property: EnterNextCtrl: Boolean If this is TRUE (standard), the Focus will jump to next Control if the user press ENTER. If it is FALSE it will show standard-behaviour (beep). This functionality is included in OnKeyPress-Event. There the component sends the Message "WM_NextDLGCTL" to the parent Form. It's important to get the ParentForm, because the TMyEdit need not included on TForm directly but maybe on a TPanel. So you have to send the message directly to the parent-FORM (and not to PARENT, which may be a TPanel). It should be possible to use this way for other components which have a OnKeyPress-Event. type TMyEdit = class(TEdit) private FEnterNextCtrl: Boolean; protected procedure KeyPress(var Key: Char); override; published property EnterNextCtrl: Boolean read FEnterNextCtrl write FEnterNextCtrl; constructor Create(AOwner: TComponent); override; end; constructor TMyEdit.Create(AOwner: TComponent); begin inherited; FEnterNextCtrl := TRUE; end; procedure TMyEdit.KeyPress(var Key: Char); var ParentForm: TCustomForm; begin inherited; if key = #13 then begin Key := #0; //Get the parent-Form. ParentForm := GetParentForm(self); if FEnterNextCtrl = TRUE {//Jump to next Control or beep } then parentform.Perform(WM_NextDLGCTL, 0, 0) else messageBeep(0); end; end; |