//遮罩句柄
IOverlaySplashScreenHandle splashHandle = null;

IWorkbook workbook = excelControl.Document;
                try
                {
                    splashHandle = SplashScreenManager.ShowOverlayForm(excelControl);
                    workbook.LoadDocument(tbFilePath.EditValue.ToString());
                }
                catch
                {
                    Common.MessageUtil.ShowErrorHint("加载文件错误");
                }
                finally
                {
                    if (splashHandle != null)
                        SplashScreenManager.CloseOverlayForm(splashHandle);
                }