小弟曾經詢問過有關排程 http://delphi.ktop.com.tw/topic.php?TOPIC_ID=54928
感謝 阿子 提供範例 但是拷貝部份程式碼過來使用, 卻發生奇怪錯誤, 只好再上來請教 (另開主題是為了可以給答題者分數) 下面紅色那行會出現 [Error] Unit1.pas(67): Constant object cannot be passed as var parameter 錯誤

<textarea class="delphi" rows="10" cols="60" name="code">
unit Unit1;    interface    uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs,
   ComCtrls, StdCtrls, ActiveX, ImgList, MsTask, MsTaskUtils, Menus,
  Shellapi;    type
  TForm1 = class(TForm)
    Memo1: TMemo;
    eComputerName: TEdit;
    lvTasks: TListView;
    SmallImageList: TImageList;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;    var
  Form1: TForm1;
  SchedulingAgent: ITaskScheduler;
  ScheduledWorkItem: IScheduledWorkItem;
  pIPersistFile: IPersistFile;
  Task: ITask;    implementation
uses AuxProcs;
{$R *.dfm}    function Init(): HRESULT;
begin
  Result := S_OK;
  if not assigned(SchedulingAgent) then
  begin
    Result := ActiveX.CoInitialize(nil);
    if Result <> S_OK then
    begin
      ActiveX.CoUninitialize;
      ShowMessage('Error in ActiveX.CoInitialize.Error Code :'   IntToHex(Result, 8));
      Application.Terminate;
    end;        Result := ActiveX.CoCreateInstance(CLSID_CSchedulingAgent,
      nil,
      CLSCTX_INPROC_SERVER,
      IID_ITaskScheduler,
      SchedulingAgent);
    if Result <> S_OK then
    begin
      ShowMessage('Error in ActiveX.CoCreateInstance.Error Code :'   IntToHex(Result, 8));
      Application.Terminate;
    end;      end;
end;
function GetITask(TaskName: string): ITask;
var
  PITask: IUnknown;
  hr: HRESULT;
begin
   hr := SchedulingAgent.Activate(StrToWide(TaskName), IID_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 TForm1.FormCreate(Sender: TObject);
var
  hr: HRESULT;
  pEnum: IEnumWorkItems;
  TaskNames: PLPWSTR;
  dwFetched: DWORD;
  szString: string;
  ListItem: TListItem;
  TriggCount: Word;
  Appname: PWideChar;
  IconIndex: Word;
  Icon: TIcon;
  TriggStr: PwideChar;
  NextRunTime: _SYSTEMTIME;
  ComputerName: PWideChar;    begin
  Icon := TIcon.Create;
  IconIndex := 0;      {used to fill edtGetTargetComputer for checking if targetcomputer is local or
  not so that the icons of the programs are not added to imagelist and listview
  if tasks are of remote computer }
//  BtnGetTargetComputerClick(self);
//  BtnStartClick(self);
  hr := StartScheduler;
  if hr = ERROR_SUCCESS then Memo1.Lines.Add('Task Scheduler started successfully.')
  else Memo1.Lines.Add('Task Scheduler did not start. Error Code:'   IntTohex(hr, 8));
  Init;      hr := SchedulingAgent.GetTargetComputer(ComputerName);
  if hr = S_OK then
  begin
    Memo1.Lines.Add('Target Computername is :'   WideCharToString(ComputerNAme)   #13#10);
    eComputerName.Text := WideCharToString(ComputerNAme);
  end
  else Memo1.Lines.Add('GetTargetComputer failed with error code :$'   IntTohex(hr, 8)   #13#10);      hr := SchedulingAgent.Enum(pEnum);
  if hr <> S_OK then Memo1.Lines.Add('SchedulingAgent.Enum Result:'   IntTohex(hr, 8));      lvTAsks.Items.Clear;
  SmallImageList.Clear; //or icons of previous get tasks will appear when another computer is selected
  while (pEnum.Next(1, TaskNames, dwFetched) = 0) and (dwFetched > 0) do
  begin    //Taskname from enum
    szString := WideCharToString(TaskNames^);
    Memo1.Lines.Add('Enum.Next fetched:'   IntToStr(dwFetched)   'item(s).'   'Taskname :'   szString);        ListItem := lvTasks.Items.Add;
    ListItem.Caption := szString;    //for getting the icon from filename of task
    Task := GetITask(szString);
    Task.GetApplicationName(Appname);    //if we try to extract an icon for a file on a remote machine our program will crash so extract only if fileexists
//Itask.GetTargetComputer retrieves computername with '\\' so while checking with local computername we add that too        if eComputerName.Text = '\\'   GetLocalComputerName then
    begin
      Icon.Handle := ExtractAssociatedIcon(Hinstance, PChar(WideCharToString(Appname)), IconIndex);
      ListItem.ImageIndex := SmallImageLIst.AddIcon(Icon);
    end;
//GetWorkingDir
    Task.GetWorkingDirectory(Appname);
    ListItem.SubItems.Add(WideCharToString(Appname));    //GetStatus
    Task.GetStatus(hr);
    ListItem.SubItems.Add(MessageFromValue(hr));
//GetNextRecentTime
    hr := Task.GetNextRunTime(NextRunTime);
    if hr = S_OK then ListItem.SubItems.Add(DateTimeToStr(SystemTimeToDateTime(NextRunTime)))
    else ListItem.SubItems.Add(MessageFromValue(hr)); ;
//GetMostRecentTime
    hr := Task.GetMostRecentRunTime(NextRunTime);
    if hr = S_OK then ListItem.SubItems.Add(DateTimeToStr(SystemTimeToDateTime(NextRunTime)))
    else ListItem.SubItems.Add(MessageFromValue(hr)); ;
//GetTriggerString and GetTriggerCount
    hr := Task.GetTriggerCount(TriggCount);
    if hr = S_OK then
      if TriggCount > 1 then
      begin
        ListItem.SubItems.Add('Multiple schedule times');
      end
      else
      begin
        Task.GetTriggerString(0, TriggStr);
        if TriggStr <> nil then ListItem.SubItems.Add(WideCharToString(TriggStr));
      end;    ///////////////////////////////////////
    ActiveX.CoTaskMemFree(TaskNames);
  end;      Icon.free;    end;    end.
</textarea>     

發表人 - pcboy2 於 2004/11/19 14:25:07 發表人 - pcboy2 於 2004/11/19 14:27:24

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能力不足，求助於人；有能力時，幫幫別人；如果您滿意答覆，請適時結案！

子曰：問有三種，不懂則問，雖懂有疑則問，雖懂而想知更多則問！

如果小弟宣告 IID_ITask : TGUID, 編譯可過, 但是執行錯誤

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能力不足，求助於人；有能力時，幫幫別人；如果您滿意答覆，請適時結案！

子曰：問有三種，不懂則問，雖懂有疑則問，雖懂而想知更多則問！

小弟發現 MsTask.pas 有下面設定

<textarea class="delphi" rows="10" cols="60" name="code">
const
  IID_ITask: TGUID = '{148BD524-A2AB-11CE-B11F-00AA00530503}';
</textarea> 

於是將自己程式略作修改

<textarea class="delphi" rows="10" cols="60" name="code">
function GetITask(TaskName: string): ITask;
var
  PITask: IUnknown;
  hr: HRESULT;
  IID_ITask2 : TGUID;
begin
  IID_ITask2 := IID_ITask;
  hr := SchedulingAgent.Activate(StrToWide(TaskName), IID_ITask2,  PITask);
</textarea> 

執行成功了 有誰可以告訴小弟, 為何原作者可以正常使用, 小弟必須這樣修改 ? 發表人 - pcboy2 於 2004/11/19 16:24:58

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能力不足，求助於人；有能力時，幫幫別人；如果您滿意答覆，請適時結案！

子曰：問有三種，不懂則問，雖懂有疑則問，雖懂而想知更多則問！