Thanks to Rob Kennedy for pointing me in the direction of ShGetFileInfo. I then Googled on that and found these two examples - Delphi 3000, Torry's. From that I wrote the following class to do what I needed.
Also, just as I was finishing up Bill Miller's answer gave me the final bit of help I needed. Originally I was passing full file names through to ShGetFileInfo, which wasn't ideally what I wanted. The tweak suggested of passing "*.EXT" was great.
The class could do with more work but it does what I need. It seems to handle file extensions that have no details associated either.
Finally, in what I'm using I've switched it to using a TcxImageList instead of a TImageList, since I was having problems with black borders appearing on the icons, because it was a quick fix.
unit FileAssociationDetails;
{
Created : 2009-05-07
Description : Class to get file type description and icons.
* Extensions and Descriptions are held in a TStringLists.
* Icons are stored in a TImageList.
Assumption is all lists are in same order.
}
interface
uses Classes, Controls;
type
TFileAssociationDetails = class(TObject)
private
FImages : TImageList;
FExtensions : TStringList;
FDescriptions : TStringList;
public
constructor Create;
destructor Destroy; override;
procedure AddFile(FileName : string);
procedure AddExtension(Extension : string);
procedure Clear;
procedure GetFileIconsAndDescriptions;
property Images : TImageList read FImages;
property Extensions : TStringList read FExtensions;
property Descriptions : TStringList read FDescriptions;
end;
implementation
uses SysUtils, ShellAPI, Graphics, Windows;
{ TFileAssociationDetails }
constructor TFileAssociationDetails.Create;
begin
try
inherited;
FExtensions := TStringList.Create;
FExtensions.Sorted := true;
FDescriptions := TStringList.Create;
FImages := TImageList.Create(nil);
except
end;
end;
destructor TFileAssociationDetails.Destroy;
begin
try
FExtensions.Free;
FDescriptions.Free;
FImages.Free;
finally
inherited;
end;
end;
procedure TFileAssociationDetails.AddFile(FileName: string);
begin
AddExtension(ExtractFileExt(FileName));
end;
procedure TFileAssociationDetails.AddExtension(Extension : string);
begin
Extension := UpperCase(Extension);
if (Trim(Extension) <> '') and
(FExtensions.IndexOf(Extension) = -1) then
FExtensions.Add(Extension);
end;
procedure TFileAssociationDetails.Clear;
begin
FExtensions.Clear;
end;
procedure TFileAssociationDetails.GetFileIconsAndDescriptions;
var
Icon: TIcon;
iCount : integer;
Extension : string;
FileInfo : SHFILEINFO;
begin
FImages.Clear;
FDescriptions.Clear;
Icon := TIcon.Create;
try
// Loop through all stored extensions and retrieve relevant info
for iCount := 0 to FExtensions.Count - 1 do
begin
Extension := '*' + FExtensions.Strings[iCount];
// Get description type
SHGetFileInfo(PChar(Extension),
FILE_ATTRIBUTE_NORMAL,
FileInfo,
SizeOf(FileInfo),
SHGFI_TYPENAME or SHGFI_USEFILEATTRIBUTES
);
FDescriptions.Add(FileInfo.szTypeName);
// Get icon and copy into ImageList
SHGetFileInfo(PChar(Extension),
FILE_ATTRIBUTE_NORMAL,
FileInfo,
SizeOf(FileInfo),
SHGFI_ICON or SHGFI_SMALLICON or
SHGFI_SYSICONINDEX or SHGFI_USEFILEATTRIBUTES
);
Icon.Handle := FileInfo.hIcon;
FImages.AddIcon(Icon);
end;
finally
Icon.Free;
end;
end;
end.
Also here is an example test app using it, it's very simple, just a form with a TPageControl on it. My actual use was not for this, but for with a Developer Express TcxImageComboxBox in a TcxGrid.
unit Main;
{
Created : 2009-05-07
Description : Test app for TFileAssociationDetails.
}
interface
uses
Windows, Forms, FileAssociationDetails, Classes, Controls, ComCtrls;
type
TfmTest = class(TForm)
PageControl1: TPageControl;
procedure FormShow(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
private
{ Private declarations }
FFileDetails : TFileAssociationDetails;
public
{ Public declarations }
end;
var
fmTest: TfmTest;
implementation
{$R *.dfm}
procedure TfmTest.FormShow(Sender: TObject);
var
iCount : integer;
NewTab : TTabSheet;
begin
FFileDetails := TFileAssociationDetails.Create;
FFileDetails.AddFile('C:\Documents and Settings\...\Test.XLS');
FFileDetails.AddExtension('.zip');
FFileDetails.AddExtension('.pdf');
FFileDetails.AddExtension('.pas');
FFileDetails.AddExtension('.XML');
FFileDetails.AddExtension('.poo');
FFileDetails.GetFileIconsAndDescriptions;
PageControl1.Images := FFileDetails.Images;
for iCount := 0 to FFileDetails.Descriptions.Count - 1 do
begin
NewTab := TTabSheet.Create(PageControl1);
NewTab.PageControl := PageControl1;
NewTab.Caption := FFileDetails.Descriptions.Strings[iCount];
NewTab.ImageIndex := iCount;
end;
end;
procedure TfmTest.FormClose(Sender: TObject; var Action: TCloseAction);
begin
PageControl1.Images := nil;
FFileDetails.Free;
end;
end.
Thanks everyone for your answers!
