With Delphi 10 Seattle, I need to get the text content of any file.
I've tried with GetFileContentsFromIFilter in SPFilter.pas from http://develop.shorterpath.com/spfree/default.asp, but I could not get it to work:
uses SPFilter;
procedure TForm1.btnTestClick(Sender: TObject);
var
FilterStream: TStringStream;
begin
FilterStream := TStringStream.Create;
try
if SPFilter.GetFileContentsFromIFilter(Trim(edtFile.Text), FilterStream) then // D:\Readme.txt
begin
FilterStream.Seek(0, soFromBeginning);
Memo1.Lines.LoadFromStream(FilterStream);
end;
finally
FilterStream.Free;
end;
end;
This is the SPFilter.pas unit:
(******************************************************************************)
(* SPFilter - Read file content using IFilter interface *)
(* Shorter Path Free Components 1.0 *)
(* *)
(* Copyright (c) 2003 Shorter Path Software *)
(* http://develop.shorterpath.com *)
(******************************************************************************)
unit SPFilter;
interface
uses
CodeSiteLogging,
Classes;
function GetFileContentsFromIFilter(const FileName: string; OutData: TStream): Boolean;
implementation
uses
Windows, SysUtils, Registry, ActiveX, Filter;
function GetFileContentsFromIFilter(const FileName: string;
OutData: TStream): Boolean;
var
Reg: TRegistry;
DocType, DocClass, HandlerClass, PersistClass, FilterDLL: string;
DLLHandle: THandle;
ClassFactory: IClassFactory;
FilterObj: IFilter;
PersistFile: IPersistFile;
DllGetClassObject: TDllGetClassObject;
DllCanUnloadNow: TDLLCanUnloadNow;
Res, ChunkRes: HResult;
pFlags: ULONG;
WFileName: WideString;
StatChunk: TStatChunk;
cwcBuffer: ULONG;
awcBuffer: PWideChar;
Txt: WideString;
AnsiTxt: string;
t: string;
EndOfChunksCount: Integer;
begin
Result := False;
{ Find filter DLL }
FilterDLL := EmptyStr;
{ Step 1: Determine the CLSID }
Reg := TRegistry.Create(KEY_READ);
Reg.RootKey := HKEY_LOCAL_MACHINE;
{ A. Locate document type }
DocType := 'Software\Classes\' + ExtractFileExt(FileName);
if Reg.OpenKey(DocType, False) then
begin
DocType := Reg.ReadString(EmptyStr);
Reg.CloseKey;
CodeSite.Send('document type', DocType); // -> txtfile
if Length(DocType) > 0 then
begin
{ B. Locate document class }
if Reg.OpenKey('Software\Classes\' + DocType + '\CLSID', False) then // FALSE HERE!!
begin
CodeSite.Send('CLSID');
DocClass := Reg.ReadString(EmptyStr);
Reg.CloseKey;
end;
end;
{ Step 2: Determine the Persistent Handler }
if Length(DocClass) > 0 then
begin
if Reg.OpenKey('Software\Classes\CLSID\' + DocClass + '\PersistentHandler', False) then
begin
HandlerClass := Reg.ReadString(EmptyStr);
Reg.CloseKey;
end;
end;
{ Step 3: Determine the IFilter Persistent Handler GUID }
if Length(HandlerClass) > 0 then
begin
if Reg.OpenKey('Software\Classes\CLSID\' + HandlerClass +
'\PersistentAddinsRegistered\' + GUIDToString(IID_IFilter), False) then
begin
PersistClass := Reg.ReadString(EmptyStr);
Reg.CloseKey;
end;
end;
{ Step 4: Determine the Filter DLL }
if Length(PersistClass) > 0 then
begin
if Reg.OpenKey('Software\Classes\CLSID\' + PersistClass + '\InprocServer32', False) then
begin
FilterDLL := Reg.ReadString(EmptyStr);
Reg.CloseKey;
end;
end;
end;
Reg.Free;
{ Use Filter DLL to read the file }
if Length(FilterDLL) > 0 then
begin
DLLHandle := LoadLibrary(PChar(FilterDLL));
if DLLHandle <> 0 then
begin
@DllGetClassObject := GetProcAddress(DLLHandle, 'DllGetClassObject');
@DllCanUnloadNow := GetProcAddress(DLLHandle, 'DllCanUnloadNow');
if Assigned(DllGetClassObject) then
begin
{ Get Class Factory }
DllGetClassObject(StringToGUID(PersistClass), IClassFactory, ClassFactory);
if Assigned(ClassFactory) then
begin
{ Get IFilter object }
ClassFactory.CreateInstance(nil, IFilter, FilterObj);
if Assigned(FilterObj) then
begin
FilterObj.QueryInterface(IPersistFile, PersistFile);
if Assigned(PersistFile) then
begin
WFileName := FileName;
PersistFile.Load(PWideChar(WFileName), 0);
EndOfChunksCount := 0;
Res := FilterObj.Init(0, 0, nil, pFlags);
if Res = S_OK then
//if FilterObj.Init(0, 0, nil, pFlags) = S_OK then
begin
repeat
ChunkRes := FilterObj.GetChunk(StatChunk);
if ChunkRes = S_OK then
begin
if (StatChunk.flags and CHUNK_TEXT) <> 0 then
begin
GetMem(awcBuffer, 16384*2);
repeat
cwcBuffer := 16384;
FillChar(awcBuffer^, cwcBuffer, 0);
Res := FilterObj.GetText(cwcBuffer, awcBuffer);
if cwcBuffer > 0 then
begin
SetLength(Txt, cwcBuffer*2);
FillChar(PWideChar(Txt)^, cwcBuffer*2, 0);
Move(awcBuffer^, PWideChar(Txt)^, cwcBuffer*2);
SetLength(AnsiTxt, cwcBuffer*2);
FillChar(PChar(AnsiTxt)^, cwcBuffer*2, 0);
WideCharToMultiByte(CP_ACP, 0, PWideChar(Txt),
cwcBuffer, PAnsiChar(AnsiTxt), cwcBuffer*2, ' ', nil);
SetLength(AnsiTxt, StrLen(PChar(AnsiTxt)));
t := t + AnsiTxt;
end;
until Res = FILTER_E_NO_MORE_TEXT;
FreeMem(awcBuffer);
end;
end;
if ChunkRes = FILTER_E_END_OF_CHUNKS then
Inc(EndOfChunksCount) else
EndOfChunksCount := 0;
until EndOfChunksCount > 1;
{ Return True for success }
Result := True;
end;
end;
{ Release filter }
PersistFile := nil;
FilterObj := nil;
end;
{ Release Class Factory }
ClassFactory := nil;
end;
end;
if Assigned(DllCanUnloadNow) then
begin
if DllCanUnloadNow = S_OK then
FreeLibrary(DLLHandle) else
end else
FreeLibrary(DLLHandle);
end;
end;
{ Write data to stream }
if Result then
try
OutData.Write(t[1], Length(t));
except
Result := False;
end;
end;
end.
As you can see from the comment "FALSE HERE" it fails to get the CLSID of .TXT file. However, there is no CLSID key inside the txtfile registry key. So what is wrong here?
IFilter Explorer from Citeknet however does show me that there IS a valid iFilter for .TXT files!
Does anybody know how to get the content of any file?