public Activity_detail_View(string Activity_name, DateTime startdate)
        {
            InitializeComponent();

            Activity_ViewModel activity_ViewModel = new Activity_ViewModel();
            List<BitmapImage> activity_photos = activity_ViewModel.SelectActivity_byActivity_no(Activity_name, startdate);
            this.Lab_activity_name.Content = activity_ViewModel.Activity_name;
            this.Lab_activity_type.Content = activity_ViewModel.Activity_type;
            this.Lab_group.Content = activity_ViewModel.Group;
            this.Lab_activity_startdate.Content = activity_ViewModel.Activity_startdate;
            this.Lab_activity_enddate.Content = activity_ViewModel.Activity_enddate;
            this.Lab_undertake_unit.Content = activity_ViewModel.Undertake_unit;
            this.Lab_undertake.Content = activity_ViewModel.Undertaker;
            this.Lab_undertake_phone.Content = activity_ViewModel.Undertake_phone;
            this.Lab_undertake_email.Content = activity_ViewModel.Undertake_email;
            this.Lab_lecturer.Content = activity_ViewModel.Lecturer;
            this.Lab_Member.Content = activity_ViewModel.Member;
            this.Lab_Spare.Content = activity_ViewModel.Spare;
            this.Lab_Place.Content = activity_ViewModel.Place;
            this.Summary.Text = activity_ViewModel.Summary;
            this.Home_photo.Source = activity_ViewModel.Home_image;

            foreach (var row in activity_photos)
            {
                System.Windows.Controls.Image image = new System.Windows.Controls.Image();
                image.Source = row;
                this.Photos.Children.Add(image);
            }

        }
        private void btn_selectactivity_Click(object sender, RoutedEventArgs e)
        {
            Activity_ViewModel activity_ViewModel = new Activity_ViewModel();

            DateTime startdate     = ((dp_startdate.SelectedDate == null) ? DateTime.Parse("2000/01/01") : (DateTime)dp_startdate.SelectedDate);
            DateTime enddate       = ((dp_startdate.SelectedDate == null) ? DateTime.Parse("3000/01/01") : (DateTime)dp_enddate.SelectedDate);
            string   activitytype  = cbb_activitytype.Text;
            string   activitygroup = cbb_activitygroup.Text;
            List <Activity_ViewModel> activity_viewmodels = activity_ViewModel.SelectActivity_byActivity_no(startdate, enddate, activitytype, activitygroup);

            ObservableCollection <activity_list> activity_itemlist = new ObservableCollection <activity_list>();

            foreach (var row in activity_viewmodels)
            {
                activity_itemlist.Add(new activity_list()
                {
                    活動名稱 = row.Activity_name, 活動類別 = row.Activity_type, 組別 = row.Group, 活動起始時間 = row.Activity_startdate, 活動結束時間 = row.Activity_enddate, 課程人數 = row.Member
                });
            }

            this.dg_activity.ItemsSource = activity_itemlist;
        }