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can't compile demo from TaskScheduler.zip (www.delphi-jedi.org)

Posted on 2003-11-24
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Last Modified: 2007-12-19
I downloaded TaskScheduler.zip (www.delphi-jedi.org). I loaded the TaskSchDemo.dpr project and tied to compile it. I got the following error when I try to compile the demo:
What am I doing wrong with the setup(I am using Delphi 7)?


[Error] main.pas(202): Constant object cannot be passed as var parameter
[Error] main.pas(890): Constant object cannot be passed as var parameter
[Error] main.pas(891): Constant object cannot be passed as var parameter
[Fatal Error] TaskSchDemo.dpr(10): Could not compile used unit 'main.pas'



197      function GetITask(TaskName: string): ITask;
198      var
199        PITask: IUnknown;
200        hr: HRESULT;
201      begin
202        hr := SchedulingAgent.Activate(StrToWide(TaskName), IID_ITask, PITask);
203        if hr = S_OK then Result := ITask(PITask)
204        else
205        begin
206          ShowMessage('Error in SchedulingAgent.Activate.Error Code :' + IntToHex(hr, 8));
207          Result := nil;
208        end;
209
210      end;



890      procedure TfrmMain.btnNewWorkItemClick(Sender: TObject);
890      var
890        HR: HRESULT;
890        TaskName: string;
890        WorkItem: IUnknown;
890      
890      begin
890        TaskName := InputBox('Enter Task Name', 'Name?', '');
890        if TAskName = '' then
890        begin
890          ShowMessage('You have to enter a task name');
890          exit;
890        end;
890        Init;
890        HR := SchedulingAgent.NewWorkItem(StrToWide(TaskName), CLSID_CTask,
890          IID_IScheduledWorkItem, WorkItem);
890        Task := ITask(WorkItem); //required for save
890        ScheduledWorkItem := IScheduledWorkItem(WorkItem);
890        if HR = S_OK then StatusMemo.Lines.Add(Taskname + ' created successfully')
890        else
890        begin
890          StatusMemo.Lines.Add('Could not create the job ' + taskname + ' Error Code :' + IntTohex(hr, 8));
890          exit;
890        end;
890        hr := SaveTAsk;
890        if hr <> S_OK then StatusMemo.lines.add('Save task failed with error code' + IntTohex(hr, 8) + #13#10);
890        BtnGetTasksClick(self); //for updating
890      end;
0
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Question by:philippe_beauregard
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3 Comments
 
LVL 23

Accepted Solution

by:
Ferruccio Accalai earned 2000 total points
ID: 9814431
you cannot pass a constant as a variable so change code as follows:

function GetITask(TaskName: string): ITask;
var
  PITask: IUnknown;
  hr: HRESULT;
  MyIid_ITask: TGuid;
begin
  MyIid_ITask := IID_ITask;
  hr := SchedulingAgent.Activate(StrToWide(TaskName),  MyIid_ITask, PITask);
  if hr = S_OK then Result := ITask(PITask)
  else
  begin
    ShowMessage('Error in SchedulingAgent.Activate.Error Code :' + IntToHex(hr, 8));
    Result := nil;
  end;

end;

procedure TfrmMain.btnNewWorkItemClick(Sender: TObject);
var
  HR: HRESULT;
  TaskName: string;
  WorkItem: IUnknown;
  MyCLSID_CTask, MYIID_IScheduledWorkItem: TGuid;
begin
  MyCLSID_CTask := CLSID_CTask;
  MyIID_IScheduledWorkItem := IID_IScheduledWorkItem;
  TaskName := InputBox('Enter Task Name', 'Name?', '');
  if TAskName = '' then
  begin
    ShowMessage('You have to enter a task name');
    exit;
  end;
  Init;
  HR := SchedulingAgent.NewWorkItem(StrToWide(TaskName), MyCLSID_CTask,
    MyIID_IScheduledWorkItem, WorkItem);
  Task := ITask(WorkItem); //required for save
  ScheduledWorkItem := IScheduledWorkItem(WorkItem);
  if HR = S_OK then StatusMemo.Lines.Add(Taskname + ' created successfully')
  else
  begin
    StatusMemo.Lines.Add('Could not create the job ' + taskname + ' Error Code :' + IntTohex(hr, 8));
    exit;
  end;
  hr := SaveTAsk;
  if hr <> S_OK then StatusMemo.lines.add('Save task failed with error code' + IntTohex(hr, 8) + #13#10);
  BtnGetTasksClick(self); //for updating
end;

F68 ;-)

0
 

Author Comment

by:philippe_beauregard
ID: 9814497
Thanks F68,

That's exactly what was needed.

-phil

0
 
LVL 23

Expert Comment

by:Ferruccio Accalai
ID: 9814535
pleased for having helped 'u' :)
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