彩票走势图

使用TVideoGrabber捕捉摄像头，相当容易，只需几句代码即可解决问题，首先我们新建一个工程,然后从控件面板上拉取一个TVideoGrabber控件到窗体中，然后再在窗体上放置四个Button,分别将Caption设为播放，暂停，停止，关闭,name分别设为BtnPlay,BtnPause,BtnStop,BtnClose将TVideoGrabber1的VideoSource的属性设置为vs_VideoCaptureDevice

为各个按钮添加点击事件，完整代码如下：

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls, VidGrab;

type
  TForm1 = class(TForm)
    VideoGrabber1: TVideoGrabber;
    BtnPlay: TButton;
    BtnPause: TButton;
    BtnStop: TButton;
    BtnClose: TButton;
    procedure BtnPlayClick(Sender: TObject);
    procedure BtnPauseClick(Sender: TObject);
    procedure BtnStopClick(Sender: TObject);
    procedure BtnCloseClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

//开启视屏

procedure TForm1.BtnPlayClick(Sender: TObject);
begin
  videoGrabber1.StartPreview;
end;

//暂停或继续

procedure TForm1.BtnPauseClick(Sender: TObject);
begin
  if BtnPause.Caption = '暂停' then
    begin
      btnPause.Caption := '继续';
      VideoGrabber1.PausePreview;
    end
  else
    begin
      btnPause.Caption := '暂停';
      VideoGrabber1.ResumePreview;
    end;
end;

//停止视屏

procedure TForm1.BtnStopClick(Sender: TObject);
begin
  videoGrabber1.StopPreview;
end;

//关闭窗体

procedure TForm1.BtnCloseClick(Sender: TObject);
begin
  close;
end;

end.