Te pongo un ejemplo que conecta la cámara, la desconecta y hace fotos.
Prepara tu formulario con:
Tres botones: Conectar, Desconectar, Hacer foto.
Un TPanel que será la ventana de previsualización.
El código sera el siguiente:
Código Delphi
[-]
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
Button3: TButton;
Panel1: TPanel;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure FormCreate(Sender: TObject);
private
hWndC : THandle;
procedure SetResolution(Width, Height: integer);
public
end;
var
Form1: TForm1;
const
WM_CAP_START = WM_USER;
WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10;
WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11;
WM_CAP_SAVEDIB = WM_CAP_START + 25;
WM_CAP_GET_VIDEOFORMAT = WM_CAP_START + 44;
WM_CAP_SET_VIDEOFORMAT = WM_CAP_START + 45;
WM_CAP_SET_PREVIEW = WM_CAP_START + 50;
WM_CAP_SET_OVERLAY = WM_CAP_START + 51;
WM_CAP_SET_PREVIEWRATE = WM_CAP_START + 52;
WM_CAP_SET_SCALE = WM_CAP_START + 53;
function capCreateCaptureWindowA(lpszWindowName: PCHAR; dwStyle, x, y, nWidth, nHeight: integer; ParentWin: HWND; nId: integer): HWND; stdcall external 'AVICAP32.DLL';
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
begin
hWndC := capCreateCaptureWindowA('Ventana de captura', WS_CHILD or WS_VISIBLE ,0, 0, Panel1.Width,Panel1.Height,Panel1.Handle,0);
if hWndC <> 0 then
begin
SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, 0, 0);
SendMessage(hWndC, WM_CAP_SET_SCALE, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEWRATE, 40, 0);
SendMessage(hWndC, WM_CAP_SET_OVERLAY, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEW, 1, 0);
Panel1.Width:= 640;
Panel1.Height:= 480;
SetResolution(Panel1.Width, Panel1.Height);
Button2.Enabled:= true;
Button3.Enabled:= true;
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
if hWndC <> 0 then
begin
SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0);
SendMessage(hWndC, WM_CLOSE, 0, 0);
hWndC := 0;
end;
Button2.Enabled:= false;
Button3.Enabled:= false;
end;
procedure TForm1.Button3Click(Sender: TObject);
begin
if hWndC <> 0 then begin
SendMessage(hWndC,WM_CAP_SAVEDIB,0,longint(pchar(ExtractFilePath(Application.ExeName)+'test.bmp')));
end;
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
if hWndC <> 0 then begin
SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0);
end;
end;
procedure TForm1.SetResolution(Width, Height: integer);
var
bi: BITMAPINFO;
begin
SendMessage(hWndC, WM_CAP_GET_VIDEOFORMAT, sizeof(bi), Cardinal(@bi));
bi.bmiHeader.biWidth:= Width;
bi.bmiHeader.biHeight:= Height;
if SendMessage(hWndC, WM_CAP_SET_VIDEOFORMAT, sizeof(bi), Cardinal(@bi)) <> 0 then
begin
SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0);
SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, 0, 0);
Button2.Enabled:= false;
Button3.Enabled:= false;
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
Button2.Enabled:= false;
Button3.Enabled:= false;
end;
end.
En principio la resolución será de 640 x 480 pero puedes cambiarla. Ya puedes encuadrar tu foto y disparar cuando te plazca.
Saludos.