Making A Form Draggable

unit Unit1; interface uses Windows, Classes, Controls, Forms; type TForm1 = class(TForm) procedure FormMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer); private { Private declarations } public { Public declarations } end; var Form1: TForm1; X_pos: Integer; Y_pos: Integer; implementation {$R *.DFM} procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); begin X_pos := X; Y_pos := Y; end; procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer); begin if HiWord(GetAsyncKeyState(VK_LBUTTON)) > 0 then begin Form1.Left := Form1.Left + X - X_pos; Form1.Top := Form1.Top + Y - Y_pos; end; end; end.

Comments

Making a form draggable is actually fairly straightforward.  This is a useful technique on forms without titlebars and for irregularly shaped (i.e., transparent) forms.   See also: Making a Draggable Titlebar.

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