Delphi Indy流Http服务器

Question

相机将图像捕获到图像中。希望此图片可从http获得。我可以使用HTTPServer1CommandGet来显示它吗？我只想实时显示image1的图像。

Answer 1

如果您只需要在客户要求时显示最新图像，则可以执行以下操作：

type
  TGetImageStream = class(TIdSync)
  protected
    FStream: TStream;
    procedure DoSynchronize; override;
  public
    class procedure GetImage(Stream: TStream);
  end;

procedure TGetImageStream.DoSynchronize;
begin
  Form1.Image1.Bitmap.SaveToStream(FStream);
end;

class procedure TGetImageStream.GetImage(Stream: TStream);
begin
  with Create do
  try
    FStream := Stream;
    Synchronize;
  finally
    Free;
  end;
end;

procedure TForm1.HTTPServer1CommandGet(AContext: TIdContext; ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo);
var
  Strm: TMemoryStream;
begin
  Strm := TMemoryStream.Create;
  try
    TGetImageStream.GetImage(Strm);
    Strm.Position := 0;
  except
    Strm.Free;
    raise;
  end;
  AResponseInfo.ResponseNo := 200;
  AResponseInfo.ContentType := 'image/bmp';
  AResponseInfo.ContentStream := Strm;
end;

但是，如果您需要实时地实时传输摄像机图像，那将变得有些棘手。您可以通过几种不同的方式进行操作。例如，使用客户端请求：

procedure TForm1.HTTPServer1CommandGet(AContext: TIdContext; ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo);
var
  Strm: TMemoryStream;
begin
  if ARequestInfo.Document = '' then
  begin
    AResponseInfo.Redirect('/');
  end
  else if ARequestInfo.Document = '/' then
  begin
    AResponseInfo.ResponseNo := 200;
    AResponseInfo.ContentType := 'text/html';
    AResponseIno.ContentText := '<html>'+EOL+
                                '<head>'+EOL+
                                '<title>Camera Image</title>'+EOL+
                                '<meta http-equiv="Refresh" content=5>'+EOL+
                                '</head>'+EOL+
                                '<body>'+EOL+
                                '<img src="/image">'+EOL+
                                '</body>'+EOL+
                                '</html>'+EOL;
  end
  else if ARequestInfo.Document = '/image' then
  begin
    Strm := TMemoryStream.Create;
    try
      TGetImageStream.GetImage(Strm);
      Strm.Position := 0;
    except
      Strm.Free;
      raise;
    end;
    AResponseInfo.ResponseNo := 200;
    AResponseInfo.ContentType := 'image/bmp';
    AResponseInfo.ContentStream := Strm;
  end else begin
    AResponseInfo.ResponseNo := 404;
  end;
end;

使用服务器推送：

procedure TForm1.HTTPServer1CommandGet(AContext: TIdContext; ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo);
var
  Strm: TMemoryStream;
begin
  Strm := TMemoryStream.Create;
  try
    AResponseInfo.ResponseNo := 200;
    AResponseInfo.ContentType := 'multipart/x-mixed-replace; boundary=imgboundary';
    AResponseInfo.CloseConnection := False;
    AResponseInfo.WriteHeader;

    AContext.Connection.IOHandler.WriteLn('--imgboundary');
    repeat
      Strm.Clear;
      TGetImageStream.GetImage(Strm);

      AContext.Connection.IOHandler.WriteLn('Content-type: image/bmp');
      AContext.Connection.IOHandler.WriteLn;
      AContext.Connection.IOHandler.Write(Strm);
      AContext.Connection.IOHandler.WriteLn;
      AContext.Connection.IOHandler.WriteLn('--imgboundary');

      Sleep(5000);
   until False;
  finally
    Strm.Free;
  end;
end;