chkaufmann

Hi,

I have an application that still uses an MS Access as database. With the library I have I can run it on other databases as well since all requests are pure SQL (no TTable or things like that).

Now I'm looking for a replacement and I wonder, if there is a solution that could be used for cloud and offline.

The databases are not that big (about 25 tables, maximum 25'000 records each). But each customer may have up to 50-100 databases.

Ideal would be a solution where the database could be in the cloud, but there is an offline copy in case the internet connection is broken, so I can continue to work. When I'm back online, all changes would be synchronized to the server.

Now I know there is probably no easy solutions, but I'm open for ideas on how to find a good solution.

Christian

So just that I get it right: Because my return value is an interface type, the compiler adds something like this as first statement of the method:

Result := nil;

Chrisitan

Hi,

I just fixed an error in the following function. I had to add the last line where I assign tmp to Result.

Now I wonder, why I didn't get a compiler warning like "return value of function might be undefined.". I get such errors in the same project with other methods, so the options are set correctly.

Christian

class function TLnxResult.GenForEvent(AData: TLnxObject; AEventId, AAgegroupId: Integer): IBSEnumerable<IBSSwLenexResult>;
var
  data  : TLnxAbstractObject;
  clubs : TLnxCollection;
  tmp   : IBSList<IBSSwLenexResult>;
begin
  tmp := TBSGenerics.GenList<IBSSwLenexResult>;
  data := AData;
  while Assigned(data) and (data.Tag <> lxCOMPETITION)
    do data := data.Parent;
  clubs := TLnxCollection(TLnxObject(data).ChildObject[lxCLUBS]);
  if Assigned(clubs) then for var ixC := 0 to clubs.ChildCount - 1 do begin
    for var e in TLnxEntryResult.GenForClub(lxRESULTS, TLnxCollection(clubs.Objects[ixC].ChildObject[lxPERSONS]), AEventId, AAgegroupId)
      do tmp.Add(e as IBSSwLenexResult);
    for var e in TLnxEntryResult.GenForClub(lxRESULTS, TLnxCollection(clubs.Objects[ixC].ChildObject[lxRELAYS]), AEventId, AAgegroupId)
      do tmp.Add(e as IBSSwLenexResult);
  end;
  tmp.Sort(function(const AResult1, AResult2: IBSSwLenexResult): Integer
           begin
             Result := AResult1.Place(nil) - AResult2.Place(nil);
             if Result.IsZero and (AResult1.Place(nil) = BSSW_MAX_PLACE)
               then Result := AResult1.Status.AsInteger - AResult2.Status.AsInteger;
           end);
  Result := tmp; // <<<< this line was missing.
end;

5 hours ago, Stefan Glienke said:

If there is a bug with that please link to the QP entry and/or code to repro wrong behavior.

The problem is to create a reproducable case. The order of initialization sections and class constructor is at least partial random. So things work fine but if you add a unit or change one of the uses in a project, the order is different. So I don't use class constructor anymore.

In 10.3 (Rio), class constructors are implemented the same way as initialization sections of units. This means, I have no control about the order. So if I create an object of my class in an initialization section, I cannot be sure, that the class constructor for this class was already called.

Just wondering: is this problem fixed in 10.4? Or is it still done the same way?

Christian

Hi,

The color select dialog in Delphi (TColorDialog, TColorBox) looks quite old and keeping multiple custom colors available doesn't really work.

Does somebody have a recommendation to replace it?

Christian

In my application I have a TApplicationEvents object and there I use the OnMessage event.

I was wondering why this event is called all the time even then when I don't touch the mouse and/or the keyboard. Now I noticed that WM_MOUSEMOVE are sent all the time.

Is this normal - probably not - but how can I find out, where these messages come from. As soon as I move the mouse cursor outside of my applications window the messages stop.

Christian

No. In my approach is I have only two tables in the SQL database: ENTITY and ENTITYVALUE. Basically each object has one record in ENTITY with general values (id, guid, ownerid, created, modified) and then it has one record for each value in ENTITYVALUE. Like this, the database is very generic and the meta information is in the code only.

Christian

We built our own framework where we can define different entity types. Each Entity Type has 1-n values. Then we allow different relation between entity types:
- Parent / Child
- Reference
- Link (m:n relation)

At first glance a parent/child relation is the same as a mandatory reference. But somehow it feels, it's not and I try to find the rules when to choose parent/child and when to choose reference.

Can someone point me to appropriate reading?

Thanks

Christian
 

Hi,

from time to time I run into an endless AV when running grep from GExperts. Here is the stack trace. I'm not sure if this is a GExperts or a DevExpress problem:

[5005FD90]{rtl260.bpl  } System.TObject.InheritsFrom (Line 18239, "System.pas" + 6) + $0
[5005FBE2]{rtl260.bpl  } System.@IsClass (Line 17942, "System.pas" + 1) + $8
[0B4ED18C]{themeloader260.bpl} System. + $0
[0B4ED959]{themeloader260.bpl} Idetheme.Vclstyledialogshooks.TTabControlIDEDialogStyleHook.Paint + $2D
[50E05577]{vcl260.bpl  } Vcl.Themes.TCustomStyleServices.DrawParentBackground (Line 2592, "Vcl.Themes.pas" + 1) + $F
[50E05591]{vcl260.bpl  } Vcl.Themes.TCustomStyleServices.DrawParentBackground (Line 2598, "Vcl.Themes.pas" + 1) + $D
[0B4E61F2]{themeloader260.bpl} Idetheme.Vclstylehooks.TTabControlIDEStyleHook.PaintBackground + $82
[0B4D8D17]{themeloader260.bpl} Idetheme.Vclstylehooks.TIDEStyleHook.WMPaint + $EF
[0B4D8E82]{themeloader260.bpl} Idetheme.Vclstylehooks.TIDEStyleHook.WndProc + $7A
[0B4D97B0]{themeloader260.bpl} Idetheme.Vclstylehooks.TMouseTrackControlIDEStyleHook.WndProc + $0
[0B4E6AB2]{themeloader260.bpl} Idetheme.Vclstylehooks.TTabControlIDEStyleHook.WndProc + $A
[0B4D8924]{themeloader260.bpl} Idetheme.Vclstylehooks.TIDEStyleHook.HandleMessage + $A0
[0B511493]{themeloader260.bpl} Idetheme.Stylemanager.TIDEThemeStyleEngine.HandleMessage + $97
[0B511C96]{themeloader260.bpl} Idetheme.Stylemanager.TIDEThemeStyleEngine.UnRegisterSysStyleHook + $DA
[50D197BC]{vcl260.bpl  } Vcl.Controls.TWinControl.WndProc (Line 10122, "Vcl.Controls.pas" + 10) + $48
[50CF65D7]{vcl260.bpl  } Vcl.Graphics.FreeMemoryContexts (Line 7138, "Vcl.Graphics.pas" + 12) + $8
[50D19314]{vcl260.bpl  } Vcl.Controls.TWinControl.MainWndProc (Line 9977, "Vcl.Controls.pas" + 3) + $6
[501796A4]{rtl260.bpl  } System.Classes.StdWndProc (Line 17932, "System.Classes.pas" + 11) + $2
[1D14BADA]{DevEx_Main.bpl} Cxcontainer.TcxCustomInnerListBox.DoGetGestureOptions + $AFE
[1D08A9E1]{DevEx_Main.bpl} Dxhooks. + $0
[50E6EC33]{vcl260.bpl  } Vcl.Forms.TApplication.ProcessMessage (Line 10747, "Vcl.Forms.pas" + 23) + $1
[50E6EC5E]{vcl260.bpl  } Vcl.Forms.TApplication.ProcessMessages (Line 10769, "Vcl.Forms.pas" + 1) + $4

I'm using Delphi 10.3.2 and GExperts 1.3.13.77.

Christian

I have a TEdit that is a bit higher than normal in order to align it with other controls. Then I wanted to center the text vertically but there is no such property and the only solution I found is to overwrite the Paint method in a subclass. Is this really the case? Or did I miss something?

Christian

Thanks Remy, perfect solution.

Christian

But if I don't declare T:class I cannot use it in the InheritsFrom() method. Same for an IInterface with the Support method:

function TComponentHelper.FindComponents<I:IInterface>: IBSEnumerable<I>;
var
  ix  : Integer;
  lst : IBSList<I>;
  tmp : I;
begin
  lst := TBSGenerics.GenList<I>;
  for ix := 0 to ComponentCount - 1
    do if Supports(Components[ix], I, tmp)
      then lst.Add(tmp);
  Result := tmp;
end;

function TComponentHelper.FindComponents<T:class>: IBSEnumerable<T>;
var
  ix  : Integer;
  lst : IBSList<T>;
  tmp : T;
begin
  Assert(T.InheritsFrom(TComponent), 'Nur für Subklassen von TComponent');
  lst := TBSGenerics.GenList<T>;
  for ix := 0 to ComponentCount - 1 do if Components[ix].InheritsFrom(T) then begin
    TComponent(tmp) := Components[ix];
    lst.Add(tmp);
  end;
  Result := lst;
end;

Christian

Hi,

I try to create this helper:

  TComponentHelper = class helper for TComponent
  public
    function FindComponents<I:IInterface>: IBSEnumerable<I>; overload;
    function FindComponents<T:class>: IBSEnumerable<T>; overload;
  end;

but I get an error "methods with identical parameters". In my generic code I filter components either by using "InheritsFrom" or "Supports()". Therefore I need IInterface and class in the declaration or is there another way to do that?

Christian

Thanks for all hints. I already use FastMM full version, so I know, there are no memory leaks. I run a huge import from one database to another. I have to pass the data through my business classes.

Since I use interfaced objects a lot, destruction is sometimes late. Combined with caching of some complex structures it's not always obvious, where there are still references. I will try to add logging with the code of Stefan.

Christian

I have to solve some "out of memory" problems during an import in my application. My application is still 32bit and when I check the memory in the process explorer, it's not 100% clear for me, which values are critical. Here are my questions:

- What is an easy way to see the number of objects of each class during debugging? Do I have to build something on my own? Can I get this info for records as well?

- Is it worth to switch the application to 64bit?

- For 32bit, which values in the Process Explorer are critical and what are the maximum values during runtime that will be save?

Thanks for any hints and tips here.

Christian

The goal is, to avoid values for unchanged properties (Name, CharSet, Height) spread over all my controls in the DFM files. If I want my application using the Screen.MessageFont, automatic update does not work for all controls with different color and/or style.

Christian

Hi,

when I change the color and/or style (italic, underline) of the Font of any control (most of the time it's TLabel), then I get this in the DFM:

          Font.Charset = DEFAULT_CHARSET
          Font.Color = clHighlight
          Font.Height = -12
          Font.Name = 'Segoe UI'
          Font.Style = [fsBold]
          ParentFont = False
 

But the added information is only this:

          Font.Color = clHighlight
          Font.Style = [fsBold]
 

Now the only solution I see, is to write my own descendant for the control and add my own properties for Style and Color. But even then I would have to suppress usage of these properties during design time in order to leave Font/ParentFont unchanged. Or did I miss something?

Christian

Thanks for the solution.

Christian

I except the default not to be written to the DFM at all. It works for High(Integer) but it looks like it doesn't for Low(Integer).

Christian

I have a custom control and defined the following published properties:

    property MaxValue: Integer read FMaxValue write SetMaxValue default High(Integer);
    property MinValue: Integer read FMinValue write SetMinValue default Low(Integer);

It works fine for MaxValue, but for MinValue I always get this in my dfm files:

      MinValue = -2147483648

Are there limitations for default values and if yes, where can I find these?

Christian

Thanks for your answer.

You are right regarding "properly" designed forms. Unfortunately I deal with old applications, that are not perfect and I thought, if I see it with the most common font/size used today, I could just fix the major problems. Mainly fix "Top" and "Height" problem are an issue because all labels and controls are higher.

Christian

On 11/9/2019 at 11:00 PM, Anders Melander said:

And then I just make sure to set all forms ParentFont=True at design time.

 

I looked at the problem again and this seems the most reasonable solution for me. The only question that remains, how can I set the IDE font used during designing to "Segoe UI, 9pt" because right now, when I choose "ParentFont = True" then I still get "Tahoma 8pt".

Christian

When I create a new form (File - New - VCL Form) font and size is always like this:

  Font.Height = -11
  Font.Name = 'Tahoma'

but I would like to have it like this:

  Font.Height = -12
  Font.Name = 'Segoe UI'

Is there a simple way to achieve this? I remember, that I saw a sample with an IDE expert for this, but is there no way to set this default in the IDE or "per project"?

Christian
 

Follow up question: I create my own request object in my OnCommandGet event. Is there a way to have a reference to this in the current TIdContext or do I have to build my own list/container for this?

Christian