11、向其他应用程序发送模拟键：
var
h: Thandle;
begin
h := FindWindow(nil, '应用程序标题');
PostMessage(h, WM_KEYDOWN, VK_F9, 0);//发送F9键
end

12、判断当前网络连接方式：
（判断结果为MODEM、局域网或是代理服务器方式）
uses wininet;
Function ConnectionKind :boolean;
var flags: dword;
begin
Result := InternetGetConnectedState(@flags, 0);
if Result then
begin
if (flags and INTERNET_CONNECTION_MODEM) = INTERNET_CONNECTION_MODEM then
begin
showmessage('Modem');
end;
if (flags and INTERNET_CONNECTION_LAN) = INTERNET_CONNECTION_LAN then
begin
showmessage('LAN');
end;
if (flags and INTERNET_CONNECTION_PROXY) = INTERNET_CONNECTION_PROXY then
begin
showmessage('Proxy');
end;
if (flags and INTERNET_CONNECTION_MODEM_BUSY)=INTERNET_CONNECTION_MODEM_BUSY then
begin
showmessage('Modem Busy');
end;
end;
end;

13、取机器BIOS信息：
with Memo1.Lines do
begin
Add('MainBoardBiosName:'+^I+string(Pchar(Ptr($FE061))));
Add('MainBoardBiosCopyRight:'+^I+string(Pchar(Ptr($FE091))));
Add('MainBoardBiosDate:'+^I+string(Pchar(Ptr($FFFF5))));
Add('MainBoardBiosSerialNo:'+^I+string(Pchar(Ptr($FEC71))));
end;

14、解析服务器IP地址：
uses winsock
function IPAddrToName(IPAddr : String): String;
var
SockAddrIn: TSockAddrIn;
HostEnt: PHostEnt;
WSAData: TWSAData;
begin
WSAStartup($101, WSAData);
SockAddrIn.sin_addr.s_addr:= inet_addr(Pchar(IPAddr));
HostEnt:= gethostbyaddr(@SockAddrIn.sin_addr.S_addr, 4, AF_INET);
if HostEnt<>nil then result:=StrPas(Hostent^.h_name) else result:='';
end;

15、清空一个目录：
function EmptyDirectory(TheDirectory :String ; Recursive : Boolean) :
Boolean;
var
SearchRec : TSearchRec;
Res : Integer;
begin
Result := False;
TheDirectory := NormalDir(TheDirectory);
Res := FindFirst(TheDirectory + '*.*', faAnyFile, SearchRec);
try
while Res = 0 do
begin
if (SearchRec.Name <> '.') and (SearchRec.Name <> '..') then
begin
if ((SearchRec.Attr and faDirectory) > 0) and Recursive
then begin
EmptyDirectory(TheDirectory + SearchRec.Name, True);
RemoveDirectory(Pchar(TheDirectory + SearchRec.Name));
end
else begin
DeleteFile(Pchar(TheDirectory + SearchRec.Name))
end;
end;
Res := FindNext(SearchRec);
end;
Result := True;
finally
FindClose(SearchRec.FindHandle);
end;
end;

16、计算目录的大小：
function GetDirectorySize(const Adirectory: string): Integer;
var
Dir: TSearchRec;
Ret: integer;
Path: string;
begin
Result := 0;
Path := ExtractFilePath(Adirectory);
Ret := Sysutils.FindFirst(Adirectory, faAnyFile, Dir);
if Ret <> NO_ERROR then exit;
try
while ret=NO_ERROR do
begin
inc(Result, Dir.Size);
if (Dir.Attr in [faDirectory]) and (Dir.Name[1] <> '.') then
Inc(Result, GetDirectorySize(Path + Dir.Name + '\*.*'));
Ret := Sysutils.FindNext(Dir);
end;
finally
Sysutils.FindClose(Dir);
end;
end;

17、获得硬盘序列号：
var SerialNum : pdword; a, b : dword; Buffer : array [0..255] of char;
begin
if GetVolumeInformation('c:\', Buffer, SizeOf(Buffer), SerialNum, a, b, nil, 0) then Label1.Caption := IntToStr(SerialNum^);
end;

18、目录完全删除：
procedure Tform1.DeleteDirectory(strDir:String);
var
sr: TSearchRec;
FileAttrs: Integer;
strfilename:string;
strPth:string;
begin
strpth:=Getcurrentdir();
FileAttrs := faAnyFile;
if FindFirst(strpth+'\'+strdir+'\*.*', FileAttrs, sr) = 0 then
begin
if (sr.Attr and FileAttrs) = sr.Attr then
begin
strfilename:=sr.Name;
if fileexists(strpth+'\'+strdir+'\'+strfilename) then
deletefile(strpth+'\'+strdir+'\'+strfilename);
end;
while FindNext(sr) = 0 do
begin
if (sr.Attr and FileAttrs) = sr.Attr then
begin
strfilename:=sr.name;
if fileexists(strpth+'\'+strdir+'\'+strfilename) then
deletefile(strpth+'\'+strdir+'\'+strfilename);
end;
end;
FindClose(sr);
removedir(strpth+'\'+strdir);
end;
end;

19、TFileStream的操作：
//从文件流当前位置读count字节到缓冲区BUFFER
function read(var buffer;count:longint):longint;override;
//将缓冲区BUFFER读到文件流中
function write(const buffer;count:longint):longint;override;
//设置文件流当前读写指针为OFFSET
function seek(offset:longint;origin:word):longint;override;
origin={soFromBeginning,soFromCurrent,soFromEnd}
//从另一文件流中当前位置复制COUNT到当前文件流当前位置
function copyfrom(source:Tstream;count:longint):longint;
//读指定文件到文件流
var myFStream:TFileStream;
begin
myFStream:=TFileStream.create(OpenDialog1.filename,fmOpenRead);
end;

20、获得CPU序列号：
function GetCpuId:longint;assembler;register;
var
temp:longint;
begin
asm
  PUSH  EBX
  PUSH  EDI
  MOV   EDI,EAX
  MOV   EAX,1
  DW   $A20F
  MOV   TEMP,EDX
  POP   EDI
  POP   EBX
end;
result:=temp;
end;

procedure TForm1.Button1Click(Sender: Tobject);
begin
  label1.Caption:=IntToHex(GetCpuId,8);
end; 


本文来源：http://blog.csdn.net/triumph_hz/archive/2007/08/10/1735807.aspx