[SOLVED] Problem with TIcon.LoadFromResourceName
lazarus / 39-Graphics

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Dibo · 2011-03-03 19:09

Hi,

I can't load icon from TIcon.LoadFromResourceName or
LoadFromResourceHandle method. Look at this code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Button1Click(Sender: TObject);var  ico: TIcon;  r:
TResourceStream;  s: String;  h: TFPResourceHandle;begin  ico :=
TIcon.Create;  r := TResourceStream.Create(HINSTANCE, 'STATUS_DEF',
'RT_GROUP_ICON');  try    { This method can't find resource (exception
raised) }    ico.LoadFromResourceName(HINSTANCE, 'STATUS_DEF');     {
This method return some handle but LoadFromResourceHandle raise
SIGSEGV}    h := FindResource(HINSTANCE, 'STATUS_DEF',
'RT_GROUP_ICON');    if h>0 then ico.LoadFromResourceHandle(HINSTANCE,
h);     { Only this work }    ico.LoadFromStream(r);  finally   
ico.Free;    r.Free;  end;end; 
Am I doing something wrong?

Regards

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fabienwang · 2011-03-03 19:37

implementation
  {$I /path/to/your/file.lrs}

  ico.LoadFromLazarusResource('name_of_icon_in_lrs_file');

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Dibo · 2011-03-03 21:06

*lrs file is loaded corectly because with TResourceStream it works
fine. Something wrong is with TIcon methods

Edit: I am using .res files instead of .lrs

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Paul Ishenin · 2011-03-04 01:11

You can't load icon from resource the way you do this because icon
consists of more than 1 resource.

use the next code instead:
Code: [Select]ico := TIcon.Create; 
ico.LoadFromResourceName(HINSTANCE, 'STATUS_DEF');

If you still want to load it from the stream then look at the
implementation of TCustomIcon.LoadFromResourceHandle

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Dibo · 2011-03-04 12:14

@Paul, in my code above I'm calling your methods too but they doesn't
work (see comments). Only TResourceStream and ico.LoadFromStream works
without errors.

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fabienwang · 2011-03-04 12:31

Dibo, have you declared ico as a TCustomIcon to use
LoadFromResourceHandle as Paul explained?

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Dibo · 2011-03-04 13:55

Yes, but have this same problem. I think I just use TResourceStream,
this works fine

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jixian.yang · 2011-03-04 15:39

The following two function are from the Unit Graphic:

function TGraphic.GetResourceType: TResourceType;
begin
  Result := nil;
end;                   

procedure TGraphic.LoadFromResourceName(Instance: THandle; const
ResName: String);
var
  Stream: TResourceStream;
  ResType: TResourceType;
begin
  ResType := GetResourceType;
  if ResType = nil then Exit;

  Stream := TResourceStream.Create(Instance, ResName, ResType);
  try
    LoadFromStream(Stream);
  finally
    Stream.Free;
  end;
end;              

The ResType returns nil so it is impossible to load the ICON stream.

And the same function GetResourceType in the LoadFromResourceHandle
function too.

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Dibo · 2011-03-04 16:00

Yes but TIcon override this function:

function TIcon.GetResourceType: TResourceType;
begin
  Result := RT_GROUP_ICON;
end;

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Paul Ishenin · 2011-03-05 01:42

Look at TApplication.Initialize - it uses the same code to load an
application icon. If you see an icon of your application / main form -
then it is something wrong in your code / your icon.

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jixian.yang · 2011-03-05 02:34

Thanks, I learnt it is override.

Seems the RT_GROUP_ICON is not "RT_GROUP_ICON", but "ICON".

So if we change "RT_GROUP_ICON" into "ICON" in res file and include
Windows unit, it can be loaded correctly.

RC file:
STATUS_DEF   ICON    "abc.ico"
STATUS_D      ICON2   "abc.ico"


implementation

uses Windows;

{$R *.lfm}
{$R abc.res}

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
var
  ico: TIcon;
  r: TResourceStream;
  s: string;
  h: TFPResourceHandle;
begin
  ico := TIcon.Create;
  { Only this work }
  r := TResourceStream.Create(HINSTANCE, 'STATUS_D', 'ICON2');
  ico.LoadFromStream(r);
  Image1.Picture.Assign(ico);
  ShowMessage('TResourceStream.Create');
  Image1.Canvas.FillRect(0, 0, Image1.Width, Image1.Height);
  try
    { This method can't find resource (exception raised) }
    ico.LoadFromResourceName(HINSTANCE, 'STATUS_DEF');
    Image1.Picture.Assign(ico);
    ShowMessage('LoadFromResourceName');
    Image1.Canvas.FillRect(0, 0, Image1.Width, Image1.Height);

    { This method return some handle but LoadFromResourceHandle raise
SIGSEGV}
    h := FindResource(HINSTANCE, 'STATUS_DEF', RT_GROUP_ICON);
    if h > 0 then
      ico.LoadFromResourceHandle(HINSTANCE, h);
    Image1.Picture.Assign(ico);
    ShowMessage('LoadFromResourceName');
    Image1.Canvas.FillRect(0, 0, Image1.Width, Image1.Height);
  finally
    ico.Free;
    r.Free;
  end;
end;

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Dibo · 2011-03-05 14:48

Quote from: jixian.yang on March 05, 2011, 03:34:21 amSeems the
RT_GROUP_ICON is not "RT_GROUP_ICON", but "ICON".
Ehh, thats right. RT_GROUP_ICON type name misled me. Thanks, problem
solved