请问要在程序中实现监视，录象，截图功能该怎样做呢？用什么控件最好？

Question

RT

Answer 1

library VideoCap;{ Important note about DLL memory management: ShareMem must be the
  first unit in your library's USES clause AND your project's (select
  Project-View Source) USES clause if your DLL exports any procedures or
  functions that pass strings as parameters or function results. This
  applies to all strings passed to and from your DLL--even those that
  are nested in records and classes. ShareMem is the interface unit to
  the BORLNDMM.DLL shared memory manager, which must be deployed along
  with your DLL. To avoid using BORLNDMM.DLL, pass string information
  using PChar or ShortString parameters. }uses
  ShareMem,
  SysUtils,
  ExtCtrls,
  ComCtrls,
  Classes,
  Dialogs,
  windows,
  VFW in 'vfw.pas';
///
var
  ghCapWnd:HWND;
{$R *.res}
function capCreateCaptureWindowA(lpszwindowname:pchar;dstyle:longint;x:integer;y:integer;nwidth:integer;
                                  Nheight:integer;parentwin:HWND;nid:integer):HWND; stdcall external 'AVICAP32.dll';
///
function StartCap(VideoWind:TPanel):boolean;export;
begin
  StartCap := false;
  ghCapWnd:=CapCreateCaptureWindowA(Pchar('QingHuntSoft'),
                                    WS_CHILD or WS_VISIBLE,
                                    0,
                                    0,
                                    VideoWind.Width,
                                    VideoWind.Height,
                                    VideoWind.Handle,
                                    10);
   if ghCapWnd<>0 then
   try
     SendMessage(ghcapwnd,WM_CAP_DRIVER_CONNECT,0,0);
     sendmessage(ghcapwnd,WM_CAP_SET_SCALE,1,1);
     sendmessage(ghcapwnd,WM_CAP_SET_PREVIEWRATE,1,1);
     sendmessage(ghcapwnd,WM_CAP_SET_OVERLAY,1,0);
     sendmessage(ghcapwnd,WM_CAP_SET_PREVIEW,1,1);
     StartCap := true;
   Except
     StartCap := false;
     Abort;
   end;
end;
///
procedure StopCap;export;
begin
  sendmessage(ghcapwnd,WM_CAP_DRIVER_DISCONNECT,0,0);
end;
///
procedure SaveCap(SavePath:string);export;
var
  Year, Month, Day, Hour, Min, Sec, MSec: Word;
  CapParms: PCaptureParms;
  Present: TDateTime;
  PathStr,MM,DD,HH:string;
  CapFileName:String;
begin
  Present:=now;
  DecodeDate(Present,Year,Month,Day);
  DecodeTime(Present, Hour, Min, Sec, MSec);
  if Month<10 then MM:=inttostr(0)+inttostr(Month) else MM:=inttostr(month);
  if Day<10   then DD:=inttoStr(0)+inttostr(day)   else DD:=inttostr(day) ;
  if Hour<10  then HH:=inttostr(0)+inttostr(Hour)  else HH:=inttostr(Hour);
  PathStr:=SavePath+'\'+MM+'月'+DD+'日';
  if Not DireCtoryExists(PathStr) then  ForceDirectories(PathStr);
  CapFileName:=DD+'-'+HH+'.Avi';
  if GhcapWnd<>0 then
   begin
     CapCaptureGetSetup(ghCapWnd,CapParms,sizeof(TCAPTUREPARMS));
     CapParms.fLimitEnabled := false;
     CapParms.fYield := TRUE;
     CapParms.vKeyAbort := VK_ESCAPE;
     CapParms.fAbortLeftMouse := FALSE;
     CapParms.fAbortRightMouse := FALSE;
     CapCaptureSetSetup(ghCapWnd,CapParms,sizeof(TCAPTUREPARMS));
     sendmessage(ghcapwnd,WM_CAP_FILE_SET_CAPTURE_FILE,0,Longint(Pchar(PathStr+'\'+Capfilename)));
     sendmessage(ghcapwnd,WM_CAP_SEQUENCE,0,0);
   end;
end;
///
procedure StopSaveCap;export;
begin
  sendmessage(ghcapwnd,WM_CAP_STOP,0,0);
end;
///
procedure SaveCapImage(SaveDialog:TSaveDialog);export;
begin
  if ghCapWnd<>0 then
  begin
    SaveDialog.DefaultExt:='bmp';
    Savedialog.Filter:='Bitmap Files (*.Bmp)|*.bmp';
    if SaveDialog.Execute   then
       Sendmessage(ghCapWnd,WM_CAP_FILE_SAVEDIB,0,Longint(Pchar(Savedialog.FileName)));
  end;
end;
///
exports
  StartCap,
  StopCap,
  SaveCap,
  StopSaveCap,
  SaveCapImage;
begin
end.

Answer 2

上面是我以前写的一个录象，监控，拍照的DLL
但是拍照的时候没做好，但是原理是正确的
都是通过发送消息实现的
你把上面代码直接用到Form中就可以了
不过不要忘记Uses
AviCap,Ole2,Vfw 这3个文件
至于哪来
就要你自己去找了