Hallo, kannst du das Control nicht mit WS_EX_Transparent transparent machen?
Delphi-Quellcode:
type
TDeinButtonControl = class(TCustomControl)
public
procedure CreateParams(var Params: TCreateParams); override;
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
end;
//..
procedure TDeinButtonControl.CreateParams(var Params: TCreateParams);
begin
inherited CreateParams(Params);
Params.ExStyle := Params.ExStyle+WS_EX_TRANSPARENT;
// Evtl ControlStyle := ControlStyle-[csOpaque];
end;