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;
                    }
                } 
            }
        }