Disable then Enable a Procedure

[Henry Olive 5]

Good Day,

 

Procedure TForm1.MyProc;

begin

....

end;

 

TForm1..DBGrid2DblClick(Sender: TObject);
begin

  MyProc = Nil;  // i want to disable myproc  procedure, how?

  .......

  MyProc:=MyProc;  // i want to enable myproc  procedure, how?

end;

 

Thank You

 

[programmerdelphi2k 237]

it would be this?

 

private/public

TForm1.myproc(Sender: TObject);

....

 

 

form1.dbgridDblClick := nil;

 

 

.... in another place

form1.dbgridDblClick := myproc;

 

Edited March 7, 2023 by programmerdelphi2k

[programmerdelphi2k 237]

or this:

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    procedure OrThisProc(Sender: TObject);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

type
  TMyProcX = procedure(Sender: TObject);

var
  MyProcX: TMyProcX;
  MyProcY: TNotifyEvent;  // = procedure(Sender : TObject) of object;  <-- in this case, Object = Form1

procedure HelloWorld(Sender: TObject);
begin

end;

procedure TForm1.OrThisProc(Sender: TObject);
begin

end;


// to better understanding... it was edited:
begin
  // when it shouldnt be used
  MyProcX := nil;
  MyProcY := nil;

  // when, it should be...
  MyProcX := HelloWorld;
  MyProcY := OrThisProc;
  
  // before any use, test it
  if Assigned(MyProcX) then
    MyProcX(Sender);
  //
  if Assigned(MyProcY) then
    MyProcY(Sender);


end.

 

Edited March 7, 2023 by programmerdelphi2k

[SwiftExpat 65]

I think what you are looking for is this, declare a var to the type of the event.

procedure TfrmRTCaddie.LicenseEditRefresh(const AValid: boolean; AInvalidReason: string);
var
  ne: TNotifyEvent; //variable of event type
begin
  ne := edtLicKeyCode.OnChange; //set the variable to the current onchagne
  edtLicKeyCode.OnChange := nil; //set on change to nil
 //work goes here
 
  edtLicKeyCode.OnChange := ne;  //asign the event hander back to the control event
end;

 

[aehimself 396]

TMyForm = Class(TForm)
strict private
  _doit: Boolean;
[...]


Procedure TMyForm.MyProc;
Begin
  If Not _doit Then
    Exit;

  [...]
End;

TForm1..DBGrid2DblClick(Sender: TObject);
Begin
  _doit := False;
  Try
    [...]
  Finally
    _doit := True;
  End;
End;

 

[programmerdelphi2k 237]

using "conditionals" is going to make it very unsafe... any other method can undo... better "nil" ED, then nothing will happen! for sure!

 

NOTE: OF COURSE, ,any other method can UNdo it (nil...)  too... but this "way" is done by default when building your class on Delphi.

Edited March 7, 2023 by programmerdelphi2k

[Fr0sT.Brutal 900]

type TSomeProc = procedure of object;

TForm
private
  procedure DefProc;
public
  NullableProc: TSomeProc;
end

Form1.NullableProc := nil;
Form1.NullableProc := @DefProc;

 

Edited March 16, 2023 by Fr0sT.Brutal