TBindings.Clear generated address error

[TomYU]

hi,kim

FBindings:=TkbmMWBindings.Create;

FBindings.Clear;

When the Clear method is called for the second time, an address error occurs.

kbmMW 5.14 has this problem, 5.13.10 is normal.

procedure TkbmMWBindings.Clear;
begin
while TkbmMWInterlocked.Increment(FSyncUpdateRunning)>1 do
begin
TkbmMWInterlocked.Decrement(FSyncUpdateRunning);
CheckSynchronize;
end;

DisableSyncUpdate;
try
FScheduler.UnScheduleGroup(‘RUN’);
FSyncList.Clear;//The address generated by this line is wrong

delphi 10.4.2+kbmMW 5.14

best regards

Tom YU

…

[TomYU]

Because of this issue, I cannot upgrade to kbmMW 5.14!

[kimbomadsen]

I’ve made a simple test like this:

procedure TForm1.FormCreate(Sender: TObject);
var
   FBindings:TkbmMWBindings;
begin
     FBindings:=TkbmMWBindings.Create;
     FBindings.Clear;
     FBindings.Clear;
     FBindings.Free;
end;

which works perfectly well without any exceptions. Be aware that you _must_ free your binding instance before application closes.

[TomYU]

 

procedure TListDialogFrame.PrepareView;
begin
if DisplayDataSet <> nil then
begin
    ListViewSearchBox(ListView1).Text:='';
    FBindings.Clear;//*******************
    if KeyFieldName <> '' then
       FBindings.Bind(DisplayDataSet, KeyFieldName, ListView1, '');
    FBindings.Bind(DisplayDataSet,DisplayFieldName,ListView1,'#Caption');
    FBindings.Bind(DisplaydataSet,'@',ListView1,'@',[mwboTwoWay]); //双向绑定.位置同步.
    FBindings.Update;
    FBindings.UpdateEvent.Activate(True);
end
else
begin
    FBindings.Clear;//*****************
    FillListFromDisplayStringList;
end;
end;

• This reply was modified 4 years, 9 months ago by TomYU.
• This reply was modified 4 years, 9 months ago by TomYU.

[TomYU]

This problem is real in my actual project, for this reason I cannot upgrade to kbmMW 5.14.

[tomyu666]

I see, the problem is caused by this line of code：

FBindings.UpdateEvent.Activate(False);

procedure TForm1.FormCreate(Sender: TObject);
var
   FBindings:TkbmMWBindings;
begin
     FBindings:=TkbmMWBindings.Create;
     FBindings.Clear;
     FBindings.UpdateEvent.Activate(False);

     FBindings.Clear;// An error 
     FBindings.Free;
end;

[kimbomadsen]

Hi,

Yup because the update event _must_ have access to several internal resources, while at the same time it may run slightly async to the destruction of the smart binding instance. Hence the update event has the responsibility of releasing some stuff when it ends.

I did not anticipate people wanting to deactivate the update event at any time, however I appreciate that it may be a wish in certain circumstances, why I (as mentioned in a different reply) have made a change that should fix it and leave the resources be, until it is really during a smart binding instance shutdown.

/Kim

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