[HeDiBo]

Hovering over a TacFloatBtn for retrieving the Hint, there is an access violation when running my application as a WIN64 process:

Code:

procedure TacFloatComponent.OnHintTimer(Sender: TObject);
begin
if (FHintTimer <> nil) and (TObject(FHintTimer.Tag) is TacFloatBtn) then // Produces the access violation
with TacFloatBtn(FHintTimer.Tag) do begin
FHintTimer.Enabled := False;
if (AForm <> nil) and PtInRect(AForm.BoundsRect, acMousePos) then
DoShowHintWnd(TObject(FHintTimer.Tag));
end;
end;

This is the stack at the moment of the error:

Code:

System._IsClass($FFFFFFFFFB0B01E0,TClass($150E7A0))
acFloatCtrls.TacFloatComponent.OnHintTimer($7FF4FA933AE0)
Vcl.ExtCtrls.TTimer.Timer
Vcl.ExtCtrls.TTimer.WndProc($14FBB0)
System.Classes.StdWndProc(???,???,???,???)
:00007FFFB9766CC1 ; C:WINDOWSSystem32user32.dll
:00007FFFB9766693 ; C:WINDOWSSystem32user32.dll
Vcl.Forms.TApplication.ProcessMessage(???)
Vcl.Forms.TApplication.HandleMessage
Vcl.Forms.TApplication.Run

[HeDiBo]

Redefining the hint timer as this:

Code:

TsTimer = class(TTimer)
protected
FOwner: TObject;
end{class};

and making the appropriate adjustments in TacFloatBtn.pas, replacing the use of the Tag property with the FOwner property will do the trick.

The same problem could arise in procedure TsSkinProvider.StartHintTimer(TitleItem: TacTitleBarItem);

[Support]

Thank you for researching, I will check it soon.

[Support]

Hello!

Can you help me to repeat this error in the test-application? Is it possible?

[HeDiBo]

'Support' wrote:

Hello!

Can you help me to repeat this error in the test-application? Is it possible?

Your code uses a Tag (which is a NativeInt) as a pointer to a TObject (which is 64 bits Word in the Win64 binary).

That's what's wrong, I think.

But my problem is only reproducable if the object resides at an address that requires more than 63 bits and has the sign set.

By the way, my solution works, I implemented it in the appropriate places in AC and got rid of the problem.

[Support]

You are right, I will change it in the nearest release.

[HeDiBo]

'Support' wrote:

You are right, I will change it in the nearest release.

The sSkinProvider module has the same problem:

Code:

procedure TsSkinProvider.OnHintTimer(Sender: TObject);
begin
if (FHintTimer nil) and (FHintTimer.Tag 0) then begin
FHintTimer.Enabled := False;
if PtInRect(FHintRect, acMousePos) then
ShowHintWnd(TacTitleBarItem(FHintTimer.Tag)); // This causes trouble
end;
end;

Making a similar change as in TacFloatBtn, solved this problem too.

[Support]

This code will be changed in the nearest release, also.

[HeDiBo]

'Support' wrote:

This code will be changed in the nearest release, also.

Problem solved in AC 13.17

[Author]

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