multithreading - 时序和 VCL 同步(在/从线程)

Question

我想刷新 Treenode.text (耗时)并使用来自同一线程的计时器。正如我所读到的，它不建议在线程中使用 TTimer*，但是，用什么来代替呢？谢谢你。

*我想使用一些时间而不是 sleep()。不仅因为那很俗气(？)，而且我必须这样做，因为否则我只能在每一秒内刷新 treenodetext。)>>

unit master_slave

...

Tsrch_slave_thread = class(TThread)   
protected
  procedure Execute; override;
public
  master: TMaster;         
end;

TMaster = class(TObject)
private
  ...
  FMasterNode: TTreeview; 
  Fsw: TStopWatch;
  Fslave_search_thread : Tsrch_slave_thread;
  ...
end;

...

implementation

...

procedure Tsrch_slave_thread.Execute;
var
  searchactive: integer;
begin
  while not terminated do begin
    searchactive := master.CMD_LISTCNT 
    if searchactive = 1 then //(master.CMD_LISTCNT's return value = 1, if master finished search on the bus)
      exit;
    sleep(1000); //dont want to flood the master with UDP packets... (master.CMD_LISTCNT sends UDP packets)
    synchronize(procedure begin
      with FmasterNode do  
        text := text + floattostr(Fsw.ElapsedMilliseconds / 1000);
    end);
  end;
end;

Answer 1

而不是 Sleep(1000) ，使用等待事件。

例如 TSimpleEvent .

FMySimpleEvent.WaitFor(1000);

如果你想提前退出线程，覆盖 TThread.DoTerminate方法和调用:

FMySimpleEvent.SetEvent;

像这样的东西:

procedure Tsrch_slave_thread.Execute;
var
  searchactive: integer;
begin
  while not terminated do begin
    searchactive := master.CMD_LISTCNT 
    if searchactive = 1 then (master.CMD_LISTCNT's return value = 1, if search finished)
      exit;
    if (FMySimpleEvent.WaitFor(1000) = wrTimeOut) then
      synchronize(procedure begin
        with FmasterNode do  
          text := text + floattostr(Fsw.ElapsedMilliseconds / 1000);
      end);
  end;
end;

procedure Tsrch_slave_thread.DoTerminate;
begin
  Inherited;
  FMySimpleEvent.SetEvent;
end;