CODEWITHSUNDEEP
c#xamllistviewdata-bindingwin-universal-app
Robert T
Robert T

Reputation: 21

Change a ListView Setting Property in XAML from Database UWP

I have been working on this for a while. Still can't seem to get it. I am trying to have a Setter Property bound to a value in my ObservableCollection populate from my DB. I have learned that Style Setters cannot be bound in Xaml. I have read and used a good example UWP Binding in Style Setter not working. But I still can't get my UI to refect the changes. My Model in Item.cs:

namespace MyTest
{
    class Item
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public bool MyIsVisible { get; set; }
        public string MyVisibility { get; set; }

    }

My MainPage.Xaml.CS:

using System.Collections.ObjectModel;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace MyTest
{
    public sealed partial class MainPage : Page
    {
        ObservableCollection<Item>Items = new ObservableCollection<Item>();

        public MainPage()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            Items.Add(new Item() { Id = 1, Name = "Item A", MyIsVisible=true, MyVisibility = "Visible" });
            Items.Add(new Item() { Id = 2, Name = "Item B", MyIsVisible=false, MyVisibility = "Collapsed" });
            Items.Add(new Item() { Id = 3, Name = "Item C", MyIsVisible=true, MyVisibility = "Visible" });
            Items.Add(new Item() { Id = 4, Name = "Item D", MyIsVisible=true, MyVisibility = "Visible" });

            MyList.ItemsSource = Items;
        }

    }
}

My MainPage.Xaml:

<Page
    x:Class="MyTest.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MyTest"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

   <Page.Resources>
      <DataTemplate x:Name="lvDataTemplate" x:DataType="local:Item">
            <TextBlock Text="{x:Bind Path=Name}"/>
      </DataTemplate>
      <Style x:Key="lvItemStyle" TargetType="ListViewItem">
         <Setter Property="local:BindingHelper.ListViewItemVisibilityBindingPath" Value="MyVisibility"/>
      </Style>
   </Page.Resources>
    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
      <ListView Grid.Row="1" Name="MyList" Margin="12, 0, 12, 0"
                   ItemTemplate="{StaticResource lvDataTemplate}" 
                   ItemContainerStyle="{StaticResource lvItemStyle}"   />
   </Grid>
</Page>

And lastly the BindingHelper.cs:

using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Data;

namespace MyTest
{
    public class BindingHelper
    {
        public static readonly DependencyProperty ListViewItemVisibilityBindingPathProperty =
            DependencyProperty.RegisterAttached(
                "ListViewItemVisibilityBindingPath", typeof(string), typeof(BindingHelper),
                new PropertyMetadata(null, ListViewItemBindingPathPropertyChanged));

        public static string GetListViewItemVisibilityBindingPath(DependencyObject obj)
        {
            return (string)obj.GetValue(ListViewItemVisibilityBindingPathProperty);
        }

        public static void SetListViewItemVisibilityBindingPath(DependencyObject obj, string value)
        {
            obj.SetValue(ListViewItemVisibilityBindingPathProperty, value);
        }


        private static void ListViewItemBindingPathPropertyChanged(
            DependencyObject obj, DependencyPropertyChangedEventArgs e)
        {
            var propertyPath = e.NewValue as string;
            if (propertyPath != null)
            {
                var gridProperty = ListViewItem.VisibilityProperty;
                BindingOperations.SetBinding( obj, gridProperty,
                        new Binding { Path = new PropertyPath(propertyPath) });
            }
        }

    }
}

I have tried using the DB MyVisibilty (string) as well as MyIsVisible (bool) and still not able to Collapse the Visibility of Item B. I am getting no errors. It seems like the BindingHelper.ListViewItemVisibilityBindingPath is still not getting the DB value "MyVisiblity". Anybody know what I am missing?
Edit 3/14/16 - After working on this extensively. I have found what appears to be the issue. I changed the ListView to a ListBox and the code worked! There is apparently an issue/limitation to the ListView which will not allow it's Setter Properties to be set by using the Dependency Binding Helper. Can anybody think of a solution or workaround for this???

Upvotes: 0

Views: 554

Answers (1)

Clemens
Clemens

Reputation: 128061

Change the type of the MyVisibility property from string to Visibility:

class Item
{
    ...
    public Visibility MyVisibility { get; set; }
}

Upvotes: 1

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