c# - WPF Binding on Nested ItemControls with Sub Collection

Question

I have the following xaml:

<ItemsControl ItemsSource="{Binding ResearchLanguageViewModel.Filters, Mode=OneWay}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <StackPanel>
                <TextBlock Text="{Binding Path=Type}"></TextBlock>
                <TextBox Text="Search...."></TextBox>
                <ItemsControl>
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <CheckBox Content="{Binding Path=Values}"></CheckBox>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
            </StackPanel>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

With the following objects/collection(s):

public class FilterViewModel
{
    public string Type { get; set; }
    public ObservableCollection<string> Values { get; set; }
}

public class ResearchLanguageViewModel
{
    public int FirmCount { get; set; }
    public ObservableCollection<FilterViewModel> Filters { get; set; } 
}

I'm trying to bind on the Filters property and the Type property comes out fine. However, I am having trouble getting the Values collection of strings to show as a group of checkboxes. Not sure what I'm doing wrong here...

Answer 1

Values in your View Model is an array, and you are trying (I'm assuming) to create an array of Checkboxes with the values of each checkbox being the index value into that array.

In your model, you are passing in the array of values into the content of one single checkbox control. What you need to do is bind the array to the parent's ItemsSource and bind the new value to the Checkbox control's content. Something like this:

<ItemsControl ItemsSource="{Binding ResearchLanguageViewModel.Filters, Mode=OneWay}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <StackPanel>
                <TextBlock Text="{Binding Path=Type}"></TextBlock>
                <TextBox Text="Search...."></TextBox>
                <ItemsControl>
                    <ItemsControl.ItemTemplate ItemsSource={Binding Path=Values}>
                        <DataTemplate>                              
                            <CheckBox Content="{Binding Mode=TwoWay}"></CheckBox>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
            </StackPanel>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>