How can I fix EInvalidOperation related to ImageList

Question

My application (write on Delphi 7)runs correctly on Windows XP SP3 but when I try to run it on Windows 7 this exception occurs:

EInvalidOperation with message "Invalid ImageList"

This is the main application code:

  Application.Initialize;

  tmpSplash.GoNextMsg;
  Application.CreateForm(TdmImages, dmImages);

  tmpSplash.GoNextMsg; // Collegamento database
  Application.CreateForm(TdmCharter, dmCharter);


  tmpSplash.GoNextMsg; // Caricamento immagini
  Application.CreateForm(TfrMain, frMain);

  tmpSplash.GoNextMsg; // init: Anagrafica
  frameAnagrafica := TframeAnagrafica.Create(Application);

  tmpSplash.GoNextMsg; // init: Flotta
  frameFlotta := TframeFlotta.Create(Application);
  //Application.CreateForm(TframeFlotta, frameFlotta);

  ...
  ...

The module dmImages has been created correctly, such as the frMain, but when will created the object frameAnagrafica then raise the exception on the constructor method:

type
    TframeAnagrafica = class(TMyCustomFrame)
...
...

{$R *.dfm}
constructor TframeAnagrafica.Create(AOwner: TComponent);
begin
  inherited Create(AOwner); 

end;

And the "super-class" of TframeAnagrafica:

TMyCustomFrame = class(TFrame)
...
...

{$R *.dfm}

constructor TMyCustomFrame.Create(AOwner: TComponent);
begin
  inherited Create(AOwner); <-- Exception here

end;

In windows XP no problem, but using Windows 7 occurs the problem. How can I resolve this problem?

Answer 1

An exception like this can occur if you use a value for the property ColorDepth that is not supported by the current operating system. Or it can occur if you try to use a 32Bit imagelist with alpha channel (TColorDepth.cd32Bit) but do not have an XP manifest in you application. To do so, include the unit xpman in your project or choose "Enable runtime themes" at "Project > Options > Application > Appearance > Runtime themes" ind Delphi XE2 or higher.