Default-Wert aus Funktion nach timeout (D6)

[HolgerX]

Hmm..

Zitat von peterbelow:

Versuchs mal hiermit.

kleine Korrectur für D6

Delphi-Quellcode:

type
  TWorkthread = class(TTHread)
  private                         // Delphi 6 kennt noch kein strict
    FValue: Integer;
  protected
    procedure Execute; override;
  public
    property Value: Integer read FValue;
  end;

procedure TWorkthread.Execute;
begin
  // code to get the data goes here
  // for now simulate a 10 second delay
  sleep(10000);
  FValue := 666;
end;

function get_value: integer;
const
  OneSecond = 1000;
  DefaultValue = 999;
var
  LResult: dword;
  LWorker : TWorkthread;
begin
  // thread starts running immediately
  LWorker := TWorkthread.Create(False);     // TThread benötigt (False) bei D6
  try
    LResult := WaitForSingleObject(LWorker.Handle, OneSecond);
    if LResult = WAIT_OBJECT_0 then
      Result := LWorker.Value
    else if LResult = WAIT_TIMEOUT then begin
      LWorker.FreeOnTerminate := true;
      LWorker := nil;
      //abandon the thread
      Result := DefaultValue;
    end
    else
      raise Exception.CreateFmt('Thread creation failed, wait result was $%x',[LResult]);
  finally
    LWorker.Free;
  end;
end;