JusJJ

How to go through ip addresses between 192.168.1.1-192.168.1.42 are they available.

If device[1].canconnect then

deviceavailable[1] = true

else 

deviceavailable[1] = false

etc.

It is an old, huge industrial compressed air system. It is divided into sectors with a total of 42 devices, valves, dryers, coolers etc.
Some devices automatically go into sleep mode because whole system can only work at full power momentarily. Each device is controlled via an ethernet converter and, since it draws the operating voltage directly from the actuator in question, it is of course not possible to contact it.
Now, if you need to adjust an individual device to change settings in some sector, it's easier to see directly which devices are in use than to go through them one by one.

Thank you very much Remy! It seems to work that way.

One more question : What would be the best and fastest way to initially check if the devices are connected between 192.168.1.1 - 192.168.1.42?

I have a reconnection problem in an android application,using Indy TidTcpClient and TIdThreadComponent.
I've tried both the Delphi bundled and the latest Indy version.

At the beginning, the program goes through the IP addresses of the available devices.

Read and write routines work without problems, but when you try to change the IP address, almost without exception the program freezes. Sometimes it takes a few seconds, sometimes a few minutes before the program responds and about every ten times the program stops responding completely. In Windows, changing the IP address works reasonably well, but sometimes it also freezes.

Receiving works...:

try
    StartChar := TCPSocket.IOHandler.ReadChar;
    if StartChar = '%' then
    begin
      Data := TCPSocket.IOHandler.ReadLn('&');
      Payload := Data;
      TCPSocket.IOHandler.ReadBytes(ChecksumBytes, 4);
      ReceivedChecksum := BytesToString(ChecksumBytes);
      CalculatedChecksum := CRC16(Payload);
      if ReceivedChecksum = CalculatedChecksum then
      begin
        TThread.Queue(nil,
          procedure
          var
            i: Integer;
          begin
           HandleData;
          end);
      end
      else
      begin
          TThread.Queue(nil,
          procedure
          begin
           HandleChecksumError;
          end);
      end;
    end;
  except
    on E: Exception do
    begin
      TThread.Queue(nil,
        procedure
        begin
         HandleException;
        end);
      ReceiveThread.Terminate;
	  end;

...but changing IP fails: 

procedure IpSelectF.IPBtnClick(Sender: TObject);
Var
  Btn: TButton;
  NewIp: string;
begin
  if Sender is TButton then
  begin
    Btn := TButton(Sender);
    if AvailableIP[Btn.Tag] then
    begin
      TTask.Run(
        procedure
        begin
          try
            if Assigned(MainF.ReceiveThread) and MainF.ReceiveThread.Active then
            begin
              MainF.ReceiveThread.Stop;
              MainF.ReceiveThread.WaitFor;  
            end;
            if MainF.TCPSocket.Connected then
              MainF.TCPSocket.Disconnect;
            NewIp := '192.168.1.' + IntToStr(Btn.Tag);
            MainF.TCPSocket.Host := NewIp;
            try
              MainF.TCPSocket.ConnectTimeout := 3000; 
              MainF.TCPSocket.Connect;
              if MainF.TCPSocket.Connected then
              begin
                TThread.Queue(nil,
                  procedure
                  begin
                    MainF.ReceiveThread.Start;
                    ShowAlertDialog('Connected to ' + NewIp);
                  end
                );
              end
              else
              begin
                TThread.Queue(nil,
                  procedure
                  begin
                    ShowAlertDialog('Connection to ' + NewIp + ' failed.');
                  end
                );
              end;
            except
              on E: Exception do
              begin
                TThread.Queue(nil,
                  procedure
                  begin
                    ShowAlertDialog('Failed to connect to ' + NewIp + ': ' + E.Message);
                  end
                );
              end;
            end;
          except
            on E: Exception do
            begin
              TThread.Queue(nil,
                procedure
                begin
                  ShowAlertDialog('Error during IP switch: ' + E.Message);
                end
              );
            end;
          end;
        end
      ); 
    end;
  end;	  

Hi,

I have a problem with TGridPanelLayout in android. Instead of spanning 2 cols, TStringgrid span just 1 col. It works perfectly in windows but not in android. Delphi version is 11CE. 

Thank you Cristian! That did the trick.

Clever! 👏You must be very proud of yourself.

I try to receive hex data from serial port using AsyncPro. However, 0x80 returns 0x20AC. How to fix this?

I have an android app for which I would like two functions for one button.
The button would be an image that changes according to the event.
What would be the best way to do such a function?

On 5/24/2023 at 4:18 PM, programmerdelphi2k said:

here works, at least!

 

It works this way, but if you try to enlarge it, it doesn't work

I found one problem. Changing background visible -> false it is impossible to change grid size and position at runtime.

Thank you very much @programmerdelphi2k!  It is easy when you know what to do.

Is it somehow possible to change the background color and remove borders of the (string)grid in FMX?

I would like to align the data in a 4 x 10 grid but only keep the text visible and hide background and borders.

Hi,

Is there a way to prevent drawing outside the canvas?
If, for example, I have a rectangular shape on which I draw an ellipse and I want to limit the drawing to the area of the shape.

procedure TForm1.shapePaint(Sender: TObject; Canvas: TCanvas;
  const ARect: TRectF);
  var
  x,y :integer;
  circle : TRectF;
begin

    x:=round(shape.Width/2);
    y:=round(shape.Width/2);

    circle:=TRectF.Create(x-190,y-190,x+100,y+100);
    shape.Canvas.Stroke.Color:=TAlphaColors.Black;
    shape.Canvas.DrawEllipse(circle,50);
end;

Now part of it is also drawn outside the shape.

Thank you Uwe. Community edition is 10.4 and in this version you can get only code in a second edit window.

Hi,

I haven't used Delphi since version 6 but I thought now to try it again after a long break. So I downloaded community edition but noticed that floating form designer has disappeared.

I remember it was easy to design a gui in the past but now it is really difficult.

Is there any way to get a form designer full screen size?