How control keypress on process

[eldonfsr]

Hi well sorry for question but i will tried to get control on sending file to serial, how i get if user push key escape to abort sending file some idea how i can do that...

Code: Pascal  [Select][+][-]

1. procedure TFormMain.MISendfileClick(Sender: TObject);
2. var filesent:Boolean;
3.   i, tlines,incr,Coils: integer;
4.   ltext: string;
5.   VSPort:TlazSerial;
6.   VTerm:TMemo;
7.   VPBar:TProgressBar;
8.   Sbar:TSTatusBar;
9. begin
10.     Sending:=true;
11.     filesent:=false;
12.     FProgress:=0;
13.      VSPort:= TlazSerial.Create(nil);
14.      VTerm:= TMemo.Create(nil);
15.      Sbar:= TStatusbar.Create(nil);
16.      case JvPageCtrl.ActivePageIndex of
17.         0:begin  VSport:= LSp1;VTerm:=MtermSp1;Sbar1.Panels.Items[1].Style:= psOwnerDraw;SBar1.Update;Sbar:=Sbar1; Coils:=CoilsSp1 ; end;
18.         1:begin  VSport:= LSp2;VTerm:=MtermSp2;Sbar2.Panels.Items[1].Style:= psOwnerDraw;SBar2.Update;Sbar:=Sbar2; Coils:=CoilsSp2 ; end;
19.         2:begin  VSport:= LSp3;VTerm:=MtermSp3;Sbar3.Panels.Items[1].Style:= psOwnerDraw;SBar1.Update;Sbar:=Sbar3; Coils:=CoilsSp3 ; end;
20.         3:begin  VSport:= LSp4;VTerm:=MtermSp4;Sbar4.Panels.Items[1].Style:= psOwnerDraw;SBar4.Update;Sbar:=Sbar4; Coils:=CoilsSp4 ; end;
21.         4:begin  VSport:= LSp5;VTerm:=MtermSp5;Sbar5.Panels.Items[1].Style:= psOwnerDraw;SBar5.Update;Sbar:=Sbar5; Coils:=CoilsSp5 ; end;
22.      end;
23.  
24.     if( (VSPort.Active)  ) then begin
25.       Odf.Filter := 'Text files (*.txt)|*.TXT|Any file (*.*)|*.*';
26.       if( (Coils=1) or (coils=0)) then begin
27.            Odf.InitialDir:= GetCurrentDir+'\Progms\SingleCoil';
28.       end else begin
29.           Odf.InitialDir:= GetCurrentDir+'\Progms\MultipleCoil';
30.       end;
31.       if Odf.Execute then begin
32.  
33.         { First check if the file exists. }
34.         if FileExists(Odf.FileName) then begin
35.           { If it exists, load the data into the memo box. }
36.  
37.           VMTerminal.Lines.Clear;
38.           FormMain.Update;
39.           FileSent:=true;
40.           VMTerminal.Lines.LoadFromFile(Odf.FileName);
41.           tlines := VMTerminal.Lines.Count-1;
42.           VSport.WriteData(chr(27)+LineEnding);
43.           sleep(100);
44.           VSPort.WriteData('RM'+LineEnding);
45.           sleep(2000);
46.           FormMain.SetFocus;
47.           incr:= Round(100/tlines);
48.           if( Assigned(VSport) ) then begin
49.             for i := 1 to tlines  do begin  // start control process to send file
50.               ltext := VMTerminal.Lines[i-1];
51.               if( FProgress< 100) then begin
52.                  FProgress:= incr*i;
53.                  Sbar.Panels.Items[1].Text:= IntToStr(FProgress);
54.               end;
55.               Sbar.Refresh;
56.               if ((ltext = 'rm') or (ltext = 'RM') or (ltext = 'MF') or (ltext = 'EM')) then  begin
57.                 VSPort.WriteData(ltext+LineEnding);
58.                 sleep(2000);
59.               end else begin
60.                 VSPort.WriteData(ltext+LineEnding);
61.                 sleep(120);
62.               end;
63.              if Sending = false then break; // I create sending global to change false and break for
64.  
65.           end;
66.           sleep(1000);
67.         end else begin
68.           { Otherwise, raise an exception. }
69.           raise Exception.Create('File does not exist.');
70.         end;
71.       end else begin
72.         ShowMessage('Not false seleted to transfer');
73.       end;
74.  
75.     end;
76.       ;
77.     Sbar.Panels.Items[1].Style:= PsText;
78.     Sbar.Panels.Items[1].text:='' ;
79.     Sbar.Update;
80.     case JvPageCtrl.ActivePageIndex of
81.        0: begin  SBar1:= SBar;end;
82.        1: begin  SBar2:= SBar;end;
83.        2: begin  SBar3:= SBar;end;
84.        3: begin  SBar4:= SBar;end;
85.        4: begin  Sbar5:= SBar;end;
86.     end;
87.  
88.     VTerm.SetFocus;
89.   end;
90. end;
91.  
92.  

 

[regs]

As your Click method is located right in TFormMain, you can use TForm's OnKeyDown event. You need to switch on KeyPreview property for the form.

Then make some protected var in TFormMain, like FAborted. Set it to False in the beginning of MISendfileClick. And set it to True in OnKeyDown. Then check it in your loop.

procedure TFormMain.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
begin
  if Key = VK_ESCAPE then
    FAborted := True;
end;

Include LCLType in uses for key constants.

But mind that the app will be locked while you using Sleep. So even if user presses Escape he would still have to wait. I never used TLazSerial, so don't know purpose though.

[Handoko]

One can use FormKeyDown, here is the demo code:
https://forum.lazarus.freepascal.org/index.php/topic,57229.msg425440.html#msg425440

Or use GetKeyState, here is the demo code:
https://forum.lazarus.freepascal.org/index.php/topic,41089.msg284614.html#msg284614

[CM630]

What is the purpose of the SLEEPs?
The solution proposed by @regs should works, but if it does not put
application.processmessages
before the Sleeps.

[RAW]

SLEEP ?
PROCESSMESSAGES ?

Really? Is that stable production code?

And I thought people used to say: "Change the structure..."