WPF - Bind a Control to a property

Question

All is in the title, I want to do something like :

<ListBox AssignTo="{Binding ListBoxControl}" ...

Then in my ViewModel having a property like this :

public ListBox CurrentListBox 
{
    get; 
    set;
}

What I want is to easely retrieve the selected items

Could I do that?

Answer 1

your xaml should looks like

    <ListBox
        ItemsSource="{Binding List}"
        SelectedItem="{Binding Item}"/>

and your properties should looks something like

    private List<yourClass> list;
    public List<yourClass> List
    {
        get { return list; }
        set
        {
            list = value;
            RaisPropertyChanged("List");
        }
    }

    private yourClass item;
    public yourClass Item
    {
        get { return item; }
        set
        {
            item = value;
            RaisPropertyChanged("Item");
        }
    }

now you only need to set your ViewModle as DataContext and there are many many way's to do this

i'm use a very simple way to do this i create an ResourceDictionary (VMViews.xaml)

<ResourceDictionary  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

                     xmlns:vm="clr-namespace:ProjectName.namespace"
                     xmlns:vw="clr-namespace:ProjectName.namespace" >

    <DataTemplate DataType="{x:Type vm:YourVMName}">
        <vw:YourVName/>
    </DataTemplate>
</ResourceDictionary>

and in my App.xaml

<Application.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="/Path/VMViews.xaml"/>
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Application.Resources>

EDIT for SelectedItems

(this code isn't tested)

XAML

<ListBox
    ItemsSource="{Binding List}"
    SelectedItem="{Binding Item}" SelectionChanged="ListBox_SelectionChanged">
    <ListBox.Resources>
        <Style TargetType="{x:Type ListBoxItem}">
            <Setter Property="IsSelected" Value="{Binding IsSelected}" />
        </Style>
    </ListBox.Resources>
</ListBox>

now your the yourClass need to implement the IsSelected property

than you can do something like

private yourClass item;
    public yourClass Item
    {
        get { return item; }
        set
        {
            item = value;
            RaisPropertyChanged("Item");

            SelectedItems = List.Where(listItem => listItem.IsSelected).ToList();
        }
    }

    private List<yourClass> selectedItems;
    public List<yourClass> SelectedItems
    {
        get { return selectedItems; }
        set
        {
            selectedItems = value;
            RaisPropertyChanged("SelectedItems");
        }
    }

Answer 2

Another person had similar issues while trying to learn...

Take a look at this answer to help

Your property is exposed via public getter/setter (although setter can be private to your data context object).

Then, the property of the listbox "Items" will get "bound" to your exposed property.