Pascal and Delphi

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KeyPress, KeyDown not triggering event

•

Join Date: Nov 2009

Posts: 7

Reputation: CanYouHandstand is an unknown quantity at this point

Solved Threads: 0

CanYouHandstand CanYouHandstand is offline

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KeyPress, KeyDown not triggering event

19 Days Ago

Hey All

I've recently picked up a VCL delphi project and am quite new to the language. The software so far consists of a main form, with several GroupBoxes and panels covering the entire form. I'm trying to implement some user short cuts, for example when "Ctrl+1" is pressed I want all the ComboBoxs to be set to a certain position. Correct me if I'm wrong but I have added an event that triggers when a button is pressed i.e KeyDown, KeyPress, etc.. However the event does not seem to be triggering when a keyboard button is pressed. Does anyone have an idea why this could be? My only guess is that the GroupBoxes are intefering. Any thoughts / hints would be greatly appreciated!

Cheers

Cameron

•

Join Date: Oct 2009

Posts: 10

Reputation: cao is an unknown quantity at this point

Solved Threads: 4

cao

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Newbie Poster

18 Days Ago

You are attempting to trap the key stroke on the form instead of a
specific component.

Set the KeyPreview property to true or in the OnCreate Method as below
Add a FormKeyDown Event to process your requirements

 Help with Code Tags 
 Pascal and Delphi Syntax (Toggle Plain Text) 
type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Edit1: TEdit;
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.DFM}
 
procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if (key=ord('1')) and (ssCtrl in Shift) then
  begin
    Edit1.Text:='Pressed';
  { Add your code here }
    Key:=0;  // if required
  end;
 
end;
 
procedure TForm1.FormCreate(Sender: TObject);
begin
  KeyPreview:=True;
end;
 
end.
type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Edit1: TEdit;
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if (key=ord('1')) and (ssCtrl in Shift) then
  begin
    Edit1.Text:='Pressed';
  { Add your code here }
    Key:=0;  // if required
  end;

end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  KeyPreview:=True;
end;

end.

•

Join Date: Oct 2009

Posts: 10

Reputation: quaifp1 is an unknown quantity at this point

Solved Threads: 3

quaifp1

Offline

Newbie Poster

18 Days Ago

TRY This:

 Help with Code Tags 
 Pascal and Delphi Syntax (Toggle Plain Text) 
procedure TMain.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
    CASE Key OF
      Ord('1') : IF Shift = [SSCTRL] THEN
                 Edit1.Text := 'CTRL 1 - Pressed'
                 ELSE IF Shift = [SSAlt] THEN
                 Edit1.Text := 'Alt 1 - Pressed'
      End;  {CASE}
 
end;
procedure TMain.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
    CASE Key OF
      Ord('1') : IF Shift = [SSCTRL] THEN
                 Edit1.Text := 'CTRL 1 - Pressed'
                 ELSE IF Shift = [SSAlt] THEN
                 Edit1.Text := 'Alt 1 - Pressed'
      End;  {CASE}

end;

•

Originally Posted by cao

You are attempting to trap the key stroke on the form instead of a
specific component.

Set the KeyPreview property to true or in the OnCreate Method as below
Add a FormKeyDown Event to process your requirements
Help with Code Tags

Pascal and Delphi Syntax (Toggle Plain Text)
type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Edit1: TEdit;
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.DFM}
 
procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if (key=ord('1')) and (ssCtrl in Shift) then
  begin
    Edit1.Text:='Pressed';
  { Add your code here }
    Key:=0;  // if required
  end;
 
end;
 
procedure TForm1.FormCreate(Sender: TObject);
begin
  KeyPreview:=True;
end;
 
end.
type TForm1 = class(TForm) GroupBox1: TGroupBox; Edit1: TEdit; procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState); procedure FormCreate(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.DFM} procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState); begin if (key=ord('1')) and (ssCtrl in Shift) then begin Edit1.Text:='Pressed'; { Add your code here } Key:=0; // if required end; end; procedure TForm1.FormCreate(Sender: TObject); begin KeyPreview:=True; end; end.