如何判斷是否是主窗體關閉？

        我分別編寫了主窗題和子窗體的Closing事件，可當關閉主窗體時，同時也觸發了子窗體的Closing事件。這個讓我很頭疼。
不過我還是找到了解決方法。即在子窗體中加入一個　”e.CloseReason“　的事件判斷。

        // 子窗體Closing事件
        mFMEntity.FormClosing  +=   new  FormClosingEventHandler(mFMEntity_FormClosing);

         ///   <summary>
         /// 關閉時，提示自動保存事件
         ///  scott 20070828
         ///   </summary>
         ///   <param name="sender"></param>
         ///   <param name="e"></param>
         static   void  mFMEntity_FormClosing( object  sender, FormClosingEventArgs e)
        {
            //判斷是否是主窗體關閉
           注意：下邊判斷是否是主窗體關閉
             if  (e.CloseReason != CloseReason.MdiFormClosing )
            {
                ArrayList alChanged  =   new  ArrayList();
                 if  (mfrmMain.MdiChildren.Length  >   0 )
                {
                     // 判斷當前窗體是否是FMEntity
                     if  (mfrmMain.ActiveMdiChild  is  WinControls.FMEntity)
                    {
                        WinControls.FMEntity fmChanged  =  (WinControls.FMEntity)mfrmMain.ActiveMdiChild;
                         if  (fmChanged.Mode  ==   2 )
                        {
                             // 將窗體放入ArrayList中，便於傳遞
                            alChanged.Add(fmChanged);
                        }
                    }
                }
                 if  (alChanged  !=   null   &&  alChanged.Count  >   0 )
                {
                     int  iResult  =  FrontHelper.ShowExitSaveForm(alChanged);
                     switch  (iResult)
                    {
                         case   1 :
                             // save
                             foreach  (WinControls.FMEntity fmentity  in  alChanged.ToArray( typeof (WinControls.FMEntity)))
                            {
                                 // 保存資料
                                FrontHelper.SaveData();
                            }
                             break ;
                         case   - 1 :
                             // don't save
                             break ;
                         case   0 :
                             // cancel
                            e.Cancel  =   true ;
                             break ;
                         default :
                             // save
                             break ;
                    }
                }
            }  
        }

CloseReason 列舉型別

成員名稱	說明
ApplicationExitCall	已叫用 (Invoke) Application 類別的 Exit 方法。
FormOwnerClosing	正在關閉主控表單。
MdiFormClosing	正在關閉這個多重文件介面 (MDI) 表單的父表單。
None	關閉的原因尚未定義或無法判斷。
TaskManagerClosing	Microsoft Windows 工作管理員正在關閉應用程式。
UserClosing	使用者正透過使用者介面 (UI) 關閉表單，例如按下表單視窗上的 [關閉] 按鈕、選取視窗控制功能表中的 [關閉] 或按下 ALT+F4。
WindowsShutDown	關機之前，作業系統正在關閉所有應用程式。

        /// <summary>
        /// 主窗體Closing事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private   void  FMMain_FormClosing( object  sender, FormClosingEventArgs e)
        {
             if  ( this .MdiChildren.Length  >   0 )
            {
                ArrayList alChanged  =   new  ArrayList();
                 for  ( int  iForm  =   0 ; iForm  <   this .MdiChildren.Length; iForm ++ )
                {
                     if  ( this .MdiChildren[iForm]  is  WinControls.FMEntity)
                    {
                        WinControls.FMEntity fmChanged  =  (WinControls.FMEntity) this .MdiChildren[iForm];
                         if  (fmChanged.Mode  ==   2 )
                        {
                            alChanged.Add(fmChanged);
                        }
                    }
                }
                 if  (alChanged  !=   null   &&  alChanged.Count  >   0 )
                {
                     int  iResult  =  FrontHelper.ShowExitSaveForm(alChanged);
                     switch  (iResult)
                    {
                         case   1 :
                             // save
                             foreach  (WinControls.FMEntity fmentity  in  alChanged.ToArray( typeof (WinControls.FMEntity)))
                            {
                                FrontHelper.SaveData();
                            }
                             break ;
                         case   - 1 :
                             // don't save
                             break ;
                         case   0 :
                             // cancel
                            e.Cancel  =   true ;
                             break ;
                         default :
                             // save
                             break ;
                    }
                } 
            }
        }