// UTF-8文件写入函数procedure SaveUTFFile(const FileName: string; S: string; WriteHeader: Boolean = True);varMemStream: TMemoryStream;HeaderStr: String;beginif S = '' then Exit; MemStream := TMemoryStream.Create;tryif WriteHeader thenbeginHeaderStr:=#$EF#$BB#$BF;MemStream.Write(HeaderStr[1], 3);end; S := AnsiToUtf8(S);MemStream.Write(S[1], Length(S));MemStream.Position := 0; MemStream.SaveToFile(FileName);finallyMemStream.Free;end;end;// UtF-8文件读取函数function LoadUTFFile(const FileName: string; ReadHeader: Boolean = True): string;varMemStream: TMemoryStream;S, HeaderStr:string;beginResult:='';if not FileExists(FileName) then Exit;MemStream := TMemoryStream.Create;tryMemStream.LoadFromFile(FileName);if ReadHeader thenbeginSetLength(HeaderStr, 3);MemStream.Read(HeaderStr[1], 3); if HeaderStr = #$EF#$BB#$BF thenbeginSetLength(S, MemStream.Size - 3);MemStream.Read(S[1], MemStream.Size - 3);end;end elsebeginSetLength(S, MemStream.Size);MemStream.Read(S[1], MemStream.Size);end;Result := Utf8ToAnsi(S);finallyMemStream.Free;end;end;// Unicode文件写入函数procedure SaveUnicodeFile(const FileName:string; const S: string; WriteHeader: Boolean = True);varMemStream: TMemoryStream;HeaderStr: string;WStr: WideString;beginif S = '' then exit;MemStream := TMemoryStream.Create;tryif WriteHeader thenbeginHeaderStr := #$FF#$FE;MemStream.Write(HeaderStr[1], 2);end;WStr := WideString(S);MemStream.Write(WStr[1], Length(WStr)*2);MemStream.Position := 0;MemStream.SaveToFile(FileName);finallyMemStream.Free;end;end;// Unicode文件读取函数function LoadUnicodeFile(const FileName: string; ReadHeader: Boolean = True): string;varMemStream: TMemoryStream;FlagStr: String;WStr: WideString;beginResult := '';if not FileExists(FileName) then Exit;MemStream := TMemoryStream.Create;tryMemStream.LoadFromFile(FileName); if ReadHeader thenbeginSetLength(FlagStr, 2);MemStream.Read(FlagStr[1], 2);if FlagStr = #$FF#$FE thenbeginSetLength(WStr, (MemStream.Size-2) div 2);MemStream.Read(WStr[1], MemStream.Size - 2);end;end elsebeginSetLength(WStr, MemStream.Size div 2);MemStream.Read(WStr[1], MemStream.Size);end;Result := AnsiString(WStr);finallyMemStream.Free;end;end;//保存文件procedure savetofile(const FileName:string; const S: string);varF: TextFile;beginAssignFile(F, FileName); // 将文件与F变量建立连接，后面可以使用F变量对文件进行操作。Rewrite(F); // 以追加的方式打开文件Writeln(F, S); // 将S变量中的内容追加到文本尾后。CloseFile(F); // 关闭文件end;

type  TTextFormat=(tfAnsi,tfUnicode,tfUnicodeBigEndian,tfUtf8);const  TextFormatFlag:array[tfAnsi..tfUtf8] of word=($0000,$FFFE,$FEFF,$EFBB);　 function WordLoHiExchange(w:Word):Word;register;asm  XCHG AL, AHend; {
     TextFormat返回文本编码类型，sText未经处理的文本 }procedure ReadTextFile(const FileName: string;  var TextFormat: TTextFormat; var sText:string);var  w:Word;  b:Byte;begin  with TFileStream.Create(FileName,fmOpenRead or fmShareDenyNone) do  try    Read(w,2);    w:=WordLoHiExchange(w);//因为是以Word数据类型读取，故高低字节互换    if w = TextFormatFlag[tfUnicode] then      TextFormat:= tfUnicode    else if w = TextFormatFlag[tfUnicodeBigEndian] then      TextFormat:= tfUnicodeBigEndian    else if w = TextFormatFlag[tfUtf8] then    begin      Read(b,1);//这里要注意一下，UFT-8必须要跳过三个字节。      TextFormat:=tfUtf8;    end else    begin      TextFormat:=tfANSI;      Position:=0;    end;    SetLength(sText,Size-Position);    ReadBuffer(sText[1],Size-Position);  finally    Free;  end;end;