delphi 2010 : Incompatible types: 'Char' and 'AnsiChar'

seriously...you didn't know that Delphi 2009+ was Unicode?? You might want to research a little more before you buy next time.

How to fix:

No, there is no way to change from Unicode to Ansi.

You will have through your code and change it. Can you give me a line with an error so I can advise how to fix??

Yes, that's a crucial mistake to go for Delphi 2009 without knowing that "things" changed.

You will have to keep AnsiChar only for old dll interfaces, or other low-level routines that need to fix the character on 1 byte (especially all byte arrays or buffers). Other string routines should stay as Char (which is now equivalent to WideChar) as everything in the VCL and Windows NT, XP, etc... works in Unicode strings.

Article which focusses a bit more on resolving the migration problem than complaining about the change:-

http://compaspascal.blogspot.com/2009/05/upgrading-major-project-to-delphi-2009.html

Here is for instance some code that produces such error:

lpszSubject := PChar(Subject)
Incompatible types: 'Char' and 'AnsiChar'

regards

function xSendMailMAPI(const Subject, Body, FileName, SenderName, SenderEMail,
                  RecepientName, RecepientEMail: String) : Integer;
var
  message: TMapiMessage;
  lpSender,
  lpRecepient: TMapiRecipDesc;
  FileAttach: TMapiFileDesc;
  SM: TFNMapiSendMail;
  MAPIModule: HModule;
begin
try;
  FillChar(message, SizeOf(message), 0);
  with message do
  begin
    if (Subject<>'') then
    begin
      lpszSubject := PChar(Subject)
    end;
    if (Body<>'') then
    begin
      lpszNoteText := PChar(Body)
    end;
    if (SenderEMail<>'') then
    begin
      lpSender.ulRecipClass := MAPI_ORIG;
      if (SenderName='') then
      begin
        lpSender.lpszName := PChar(SenderEMail)
      end
      else
      begin
        lpSender.lpszName := PChar(SenderName)
      end;
      lpSender.lpszAddress := PChar('SMTP:'+SenderEMail);
      lpSender.ulReserved := 0;
      lpSender.ulEIDSize := 0;
      lpSender.lpEntryID := nil;
      lpOriginator := @lpSender;
    end;
    if (RecepientEMail<>'') then
    begin
      lpRecepient.ulRecipClass := MAPI_TO;
      if (RecepientName='') then
      begin
        lpRecepient.lpszName := PChar(RecepientEMail)
      end
      else
      begin
        lpRecepient.lpszName := PChar(RecepientName)
      end;
      lpRecepient.lpszAddress := PChar('SMTP:'+RecepientEMail);
      lpRecepient.ulReserved := 0;
      lpRecepient.ulEIDSize := 0;
      lpRecepient.lpEntryID := nil;
      nRecipCount := 1;
      lpRecips := @lpRecepient;
    end
    else
    begin
      lpRecips := nil
    end;
    if (FileName='') then
    begin
      nFileCount := 0;
      lpFiles := nil;
    end
    else
    begin
      FillChar(FileAttach, SizeOf(FileAttach), 0);
      FileAttach.nPosition := Cardinal($FFFFFFFF);
      FileAttach.lpszPathName := PChar(FileName);
      nFileCount := 1;
      lpFiles := @FileAttach;
    end;
  end;
  MAPIModule := LoadLibrary(PChar(MAPIDLL));
  if MAPIModule=0 then
  begin
    Result := -1
  end
  else
  begin
    try
      @SM := GetProcAddress(MAPIModule, 'MAPISendMail');
      if @SM<>nil then
      begin
        Result := SM(0, Application.Handle, message, MAPI_DIALOG or
                     MAPI_LOGON_UI, 0);
      end
      else
      begin
        Result := 1
      end;

    finally
      FreeLibrary(MAPIModule);
    end;
  end;
  if Result<>0 then
  begin
    MessageDlg('Error sending mail ('+IntToStr(Result)+').', mtError, [mbOk],
               0)
  end;
  except;end;
end;

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replace all String with AnsiString, and PChar with PAnsiChar, it should work with only string conversion before the function is called

Hi guys,
Apologies for the delay in responding, that was due to two days of absense and the fact that
I got stuck with trying to find the reasons for my problem.

It now seems that the problems that I get are due to the unicode support of recent releases of Delphi (and Delphi 2010 that I use).
I tried the several files that you sent me, I tried to change myself all the
String=>AnsiString, Char=>AnsiChar, PChar=>PAnsiChar
and I also tried to use the {$H-} compiler directive. All of them without success.

In the particular files that you sent, in all cases the error was at line 1310 of AviWriter_2.pas, in the AVIFileOpen call:

  // Open AVI file for write
  AVIERR := AVIFileOpen(pfile, PChar(Workfile), OF_WRITE or OF_CREATE, nil);
  //Shareexclusive causes nothing but trouble on an exception
  if AVIERR <> AVIERR_OK then
   raise Exception.Create('Failed to create AVI video file. Err: $' + IntToHex(AVIERR, 8));

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I get a value for AVIERR=-2147221164. I have attached an image for the error message.

When I step into AVIFileOpen the debugger gets me into System.pas: line 17000
in the function _UStrToPWChar(const S: UnicodeString): PWideChar;
where S = 'C:\Users\santon\Desktop\tmp.avi' is the path to the avi file. AviWriter-2.jpg
System-pas.jpg

Please, ignore my previous post. That was intended for a different question. Apologies...