请教fileread、fileopen和fileseek函数的用法！

Question

最好能详细说明这些函数中每个参数的含义！谢谢了！
function FileSeek(Handle: Integer;Offset: Longint;Origin: Integer):Longint;
function FileRead(Handle:Integer; var Buffer;Count:Longint):Longint;
function FileOpen(const FileName: string; Mode:Word): Integer;

Answer 1

procedure TForm1.Button1Click(Sender: TObject);var
  iFileHandle: Integer;
  iFileLength: Integer;
  iBytesRead: Integer;
  Buffer: PChar;
  i: Integer
begin
  if OpenDialog1.Execute then 
  begin
    try
      iFileHandle := FileOpen(OpenDialog1.FileName, fmOpenRead);
       iFileLength := FileSeek(iFileHandle,0,2);
      FileSeek(iFileHandle,0,0);
      Buffer := PChar(AllocMem(iFileLength + 1));
      iBytesRead := FileRead(iFileHandle, Buffer^, iFileLength);      FileClose(iFileHandle);
      for i := 0 to iBytesRead-1 do
      begin
        StringGrid1.RowCount := StringGrid1.RowCount + 1;
        StringGrid1.Cells[1,i+1] := Buffer[i];
        StringGrid1.Cells[2,i+1] := IntToStr(Integer(Buffer[i]));
      end;
    finally
      FreeMem(Buffer);
    end;
  end;
end;