访问ItemSource属性自定义控件

Question

I am trying to make a custom listbox that contains a checkbox and text. Here is the custom control class:

    public FilterChoices()
{
    InitializeComponent();
}

public IEnumerable ItemsSource
{
    get { return (IEnumerable) GetValue(ItemsSourceProperty); }
    set { SetValue(ItemsSourceProperty, value); }
}

public static readonly DependencyProperty ItemsSourceProperty =
    DependencyProperty.Register("ItemsSource", typeof(IEnumerable),
        typeof(FilterChoices));

Custom Control xaml:

        <ListBox x:Name="FilteredItems" Grid.Column="0" Grid.ColumnSpan="2" Grid.Row="2" Height="Auto" ItemsSource="{Binding}">
            <ListBox.ItemTemplate>
                <HierarchicalDataTemplate>
                    <CheckBox Content="{Binding Data}" IsChecked="{Binding IsChecked}"/>
                    <!--<CheckBox Content="{Binding Path=Data, ElementName=FilterChoiceControl}" IsChecked="{Binding Path=IsChecked, ElementName=FilterChoiceControl}"/>-->
                </HierarchicalDataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

List of objects being passed in:

public class FilterItems
{
    public string Data { get; set; }
    public bool IsChecked { get; set; }
}

I am manually setting the ItemSource in my MainWindow's code behind. If I put a breakpoint on the setter in my custom control, I can see that it is being populated with the correct data. However, the listbox appears empty upon load. If I don't use the custom control and manually add a listbox to my MainWindow's xaml, the listbox populates as intended. I would like to use a custom control so I can add other controls besides the listbox and checkboxes

Answer 1

May be the problem is with the way you're binding data. You haven't posted what is the purpose of ItemsSourceProperty in FilterChoices. Regardless from what you've said, following code binds data perfectly:

MainWindow:

public MainWindow()
{
     InitializeComponent();
     var lst = new List<FilterItems>();
     for (int i = 0; i < 100; i++)
     {
         lst.Add(new Temp.FilterItems()
         {
             Data = $"Item {i + 1}",
             IsChecked = i % 2 == 0
         });
     }
     this.DataContext = lst;
}


Xaml:
<Window x:Class="MyNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:temp="clr-namespace:MyNamespace"
        mc:Ignorable="d"
        Title="Test Assembly Runner" Height="350" Width="525">
    <temp:CustomControl DataContext="{Binding}" />
</Window>


Custom Control:
<UserControl x:Class="MyNamespace.CustomControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:local="clr-namespace:MyNamespace"
             mc:Ignorable="d"
             d:DesignHeight="300" d:DesignWidth="300">
    <ListBox x:Name="FilteredItems" Grid.Column="0" Grid.ColumnSpan="2" Grid.Row="2" Height="Auto" ItemsSource="{Binding}">
        <ListBox.ItemTemplate>
            <HierarchicalDataTemplate>
                <CheckBox Content="{Binding Data}" IsChecked="{Binding IsChecked}"/>
            </HierarchicalDataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
</UserControl>