Auto center a form in Delphi

Just call this function to center the form on the screen (for example in the OnShow event).

procedure centerizeform(f:TForm);

begin

  f.Top:=(Screen.WorkAreaHeight-f.Height) div 2;

  if f.Top<0 then f.Top:=0;

  f.Left:=(Screen.WorkAreaWidth-f.Width) div 2;

  if f.Left<0 then f.Left:=0;

end;

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If the above code doesn't work for you, just  Try This Code Below :



procedure TForm1.FormCreate(Sender: TObject);
begin
  Left:=(Screen.Width-Width)  div 2;
  Top:=(Screen.Height-Height) div 2;
end;

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Center a form on screen at runtime
 
procedure CenterForm (AForm: TForm); 

var ALeft, ATop: integer; 

begin ALeft : = (Screen.Width - AForm.Width) div 2; 

ATop : = (Screen.Height - AForm.Height) div 2; 

 

{ prevents form being twice repainted! }

AForm.SetBounds (ALeft, ATop, AForm.Width, AForm.Height); end; 

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Center a form over active form at runtime
procedure CenterFormOverActive (AForm: TForm); 

var ALeft, ATop: integer; 

begin ALeft : = Screen.ActiveForm.Left + (Screen.ActiveForm.Width div 2) - (AForm.Width div 2); 

ATop : = Screen.ActiveForm.Top + (Screen.ActiveForm.Height div 2) - (AForm.Height div 2); 

 

{ prevent form from being outside screen }

if ALeft < 0 then ALeft := Screen.ActiveForm.Left;

if ATop < 0 then ATop := Screen.ActiveForm.Top;

if (ALeft + AForm.Width > Screen.Width) or (ATop + AForm.Height > Screen.Height) then

CenterForm (AForm) else 

{ prevents form being twice repainted! } 

AForm.SetBounds (ALeft, ATop, AForm.Width, AForm.Height); end;