Question:
How can I retrieve the program that is associated with a given
extension?
Answer:
The following example demonstrates retrieving the file associated
with a file extension.
Example:
uses
{$IFDEF WIN32}
Registry; {We will get it from the registry}
{$ELSE}
IniFiles; {We will get it from the win.ini file}
{$ENDIF}
{$IFNDEF WIN32}
const MAX_PATH = 144;
{$ENDIF}
function GetProgramAssociation (Ext : string) : string;
var
{$IFDEF WIN32}
reg: TRegistry;
s : string;
{$ELSE}
WinIni : TIniFile;
WinIniFileName : array[0..MAX_PATH] of char;
s : string;
{$ENDIF}
begin
{$IFDEF WIN32}
s := '';
reg := TRegistry.Create;
reg.RootKey := HKEY_CLASSES_ROOT;
if reg.OpenKey('.' + ext + '\shell\open\command',
false) <> false then begin
{The open command has been found}
s := reg.ReadString('');
reg.CloseKey;
end else begin
{perhaps thier is a system file pointer}
if reg.OpenKey('.' + ext,
false) <> false then begin
s := reg.ReadString('');
reg.CloseKey;
if s <> '' then begin
{A system file pointer was found}
if reg.OpenKey(s + '\shell\open\command',
false) <> false then
{The open command has been found}
s := reg.ReadString('');
reg.CloseKey;
end;
end;
end;
{Delete any command line, quotes and spaces}
if Pos('%', s) > 0 then
Delete(s, Pos('%', s), length(s));
if ((length(s) > 0) and
(s[1] = '"')) then
Delete(s, 1, 1);
if ((length(s) > 0) and
(s[length(s)] = '"')) then
Delete(s, Length(s), 1);
while ((length(s) > 0) and
((s[length(s)] = #32) or
(s[length(s)] = '"'))) do
Delete(s, Length(s), 1);
{$ELSE}
GetWindowsDirectory(WinIniFileName, sizeof(WinIniFileName));
StrCat(WinIniFileName, '\win.ini');
WinIni := TIniFile.Create(WinIniFileName);
s := WinIni.ReadString('Extensions',
ext,
'');
WinIni.Free;
{Delete any command line}
if Pos(' ^', s) > 0 then
Delete(s, Pos(' ^', s), length(s));
{$ENDIF}
result := s;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(GetProgramAssociation('gif'));
end;