C# 无法使用UpdateLayout（）[UWP]刷新日历视图

在我的UWP应用程序中，我试图刷新

calendarview

上的密度条，如果用户单击按钮，问题是，尽管

calendarview.UpdateLayout（）

应重新运行

CalendarViewDayItemChangeing

事件，它仅在第一次加载

CalendarView

时运行。我做错什么了吗

 public MainPage()
        {
            this.InitializeComponent();
            densityColors.Add(Colors.Green); 
        }

      private void CalendarView_CalendarViewDayItemChanging(CalendarView sender, CalendarViewDayItemChangingEventArgs args)
            {
                item = args.Item;
                if (item < DateTimeOffset.Now)
                {
                    item.SetDensityColors(densityColors);
                }

            }

            private void Button_Click(object sender, RoutedEventArgs e)
            {
                densityColors[0]=Colors.Blue;
                calendarView.UpdateLayout();
            }

public主页（）
{
this.InitializeComponent（）；
密度颜色。添加（颜色。绿色）；
}
private void CalendarView\u CalendarViewDayItemChangeing（CalendarView发件人、CalendarViewDayItemChangingEventArgs参数）
{
项目=参数项目；
如果（项

UpdateLayout

在这里不会执行任何操作，因为没有布局更新，并且只有当您移动到另一个日历视图时才会触发

CalendarViewDayItemChangeing

 public MainPage()
        {
            this.InitializeComponent();
            densityColors.Add(Colors.Green); 
        }

      private void CalendarView_CalendarViewDayItemChanging(CalendarView sender, CalendarViewDayItemChangingEventArgs args)
            {
                item = args.Item;
                if (item < DateTimeOffset.Now)
                {
                    item.SetDensityColors(densityColors);
                }

            }

            private void Button_Click(object sender, RoutedEventArgs e)
            {
                densityColors[0]=Colors.Blue;
                calendarView.UpdateLayout();
            }

在您的情况下，只需手动定位所有

CalendarViewDayItems

，并在现有视图上更新其颜色

 public MainPage()
        {
            this.InitializeComponent();
            densityColors.Add(Colors.Green); 
        }

      private void CalendarView_CalendarViewDayItemChanging(CalendarView sender, CalendarViewDayItemChangingEventArgs args)
            {
                item = args.Item;
                if (item < DateTimeOffset.Now)
                {
                    item.SetDensityColors(densityColors);
                }

            }

            private void Button_Click(object sender, RoutedEventArgs e)
            {
                densityColors[0]=Colors.Blue;
                calendarView.UpdateLayout();
            }

首先，创建一个小的

Children

扩展方法来帮助检索相同类型的所有子项

 public MainPage()
        {
            this.InitializeComponent();
            densityColors.Add(Colors.Green); 
        }

      private void CalendarView_CalendarViewDayItemChanging(CalendarView sender, CalendarViewDayItemChangingEventArgs args)
            {
                item = args.Item;
                if (item < DateTimeOffset.Now)
                {
                    item.SetDensityColors(densityColors);
                }

            }

            private void Button_Click(object sender, RoutedEventArgs e)
            {
                densityColors[0]=Colors.Blue;
                calendarView.UpdateLayout();
            }

public static class Helper
{
    public static List<FrameworkElement> Children(this DependencyObject parent)
    {
        var list = new List<FrameworkElement>();

        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
        {
            var child = VisualTreeHelper.GetChild(parent, i);

            if (child is FrameworkElement)
            {
                list.Add(child as FrameworkElement);
            }

            list.AddRange(Children(child));
        }

        return list;
    }
}

注意：您不必担心新的

CalendarViewDayItem

进入视图，因为它们将由您的

CalendarView\u CalendarViewDayItemChangeing

回调处理

 public MainPage()
        {
            this.InitializeComponent();
            densityColors.Add(Colors.Green); 
        }

      private void CalendarView_CalendarViewDayItemChanging(CalendarView sender, CalendarViewDayItemChangingEventArgs args)
            {
                item = args.Item;
                if (item < DateTimeOffset.Now)
                {
                    item.SetDensityColors(densityColors);
                }

            }

            private void Button_Click(object sender, RoutedEventArgs e)
            {
                densityColors[0]=Colors.Blue;
                calendarView.UpdateLayout();
            }