Все можно сделать проще
| Код |
type
THComboBox=class(TComboBox)
private
HW:THintWindow;
isShowHW:boolean;
protected
procedure WMCTLCOLORLISTBOX(var Message: TMessage);//message WM_CTLCOLORLISTBOX;
procedure WndProc(var Message: TMessage); override;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy;override;
end;
implementation
{ THComboBox }
constructor THComboBox.Create(AOwner: TComponent);
begin
inherited;
HW:=THintWindow.Create(self);
HW.ActivateHint(rect(0,0,0,0),''); //Без этого, при первом показе, HW перекрывается выпадающим списком
HW.ReleaseHandle;
isShowHW:=false;
end;
destructor THComboBox.Destroy;
begin
HW.Destroy;
inherited;
end;
procedure THComboBox.WMCTLCOLORLISTBOX(var Message: TMessage);
var
ItemIndex,txtlen:cardinal;
twidth:cardinal;
cr,pi:tpoint;
txt:string;
rct:TRECT;
begin
ItemIndex:=self.ItemIndex;
if ItemIndex>=0 then
begin
txt:=self.Items[ItemIndex];
twidth:=self.Canvas.TextWidth(txt);
GetWindowRect(self.Handle,rct);
if twidth>(rct.Right-rct.Left) then
begin
pi.X:=rct.Left;
pi.Y:=rct.Top;
rct:=hw.CalcHintRect(1000,txt,nil);
getcursorpos(cr);
With rct do
begin
Left:=Left+pi.X;
Right:=Left+Right;
Top:=cr.Y+20;
Bottom:=Top+Bottom;
end;
hw.ActivateHint(rct,txt);
isShowHW:=true;
exit;
end;
end;
if isShowHW then
begin
hw.ReleaseHandle;
isShowHW:=false;
end;
end;
procedure THComboBox.WndProc(var Message: TMessage);
begin
inherited;
if Message.Msg=WM_CTLCOLORLISTBOX then WMCTLCOLORLISTBOX(Message)else if isShowHW then
begin
hw.ReleaseHandle;
isShowHW:=false;
end;
end;
end.
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