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?

If you are using MVVM pattern your ViewModel doesn't know about your View, so you shouldn't have View related properties there, like in this case `ListBox`. Your VM should only expose Model related properties which you can bind to your View, from what I understand. — Adolfo Perez, Jun 14 '13 at 13:55
Could you do what? You have written a binding that binds to `ListBoxControl` and then don't define `ListBoxControl` anywhere. If you meant to bind to `CurrentListBox` then most likely what you want to do is use a `ContentControl` instead: ``, but I'd recommend against it. — Dan Puzey, Jun 14 '13 at 13:55
I want to change a gui used for launching integration test. I have currently a binding on SelectedItem, but I want to be able to select several at the same time. I don't want to make the code enven more unreadable that he is right now doing something like : [here](http://stackoverflow.com/questions/451748/wpf-m-v-vm-get-selected-items-from-a-listcollectionview) — Thomas, Jun 14 '13 at 14:01
Why don't you wrap the items in your collection in a container that has an isSelected property and then bind to that? — jfin3204, Jun 14 '13 at 14:16

WiiMaxx · Answer 1 · 2013-06-14T14:49:57.457

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");
        }
    }

I want multiple selected Items, not only one ! `SelectedItems="{Binding SelectedTest}" SelectionMode="Extended"/>` — Thomas, Jun 14 '13 at 14:21
One is working fine by the way, why `Multiple` is such a pain? — Thomas, Jun 14 '13 at 14:26
oh sry @Thomas i thought only one so you need an behavior because you can't bind directly to SelectedItems AFAIK — WiiMaxx, Jun 14 '13 at 14:26
@Thomas see my Edit maybe that will help you it is based on [THIS](http://stackoverflow.com/a/9880673/1993545) and if it doesn't work take a look at [THIS](http://blog.functionalfun.net/2009/02/how-to-databind-to-selecteditems.html) link — WiiMaxx, Jun 14 '13 at 14:52
@Thomas and i forgot [THIS](http://stackoverflow.com/a/16953833/1993545) is the easiest solution i found — WiiMaxx, Jun 14 '13 at 14:55
@WiiMaxx I finally followed the [following post](http://stackoverflow.com/questions/451748/wpf-m-v-vm-get-selected-items-from-a-listcollectionview?answertab=active#tab-top). It looks messy for me but at least it works. — Thomas, Jun 14 '13 at 15:22

score 0 · Answer 2 · edited May 23 '17 at 12:13

0

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.

edited May 23 '17 at 12:13

Community

1
1

answered Jun 14 '13 at 14:04

DRapp

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I need access to selectedItems, when I tried to use classic binding I have :'SelectedItems' property is read-only and cannot be set from markup. – Thomas Jun 14 '13 at 14:11
@Thomas, then I would expand the properties on your model as WiiMaxx has sampled, but instead of a single "Item", you want a list of items to handle multiple item selections... but the principle is still the same. – DRapp Jun 14 '13 at 14:21
I am sorry but after reading 5 time the post you cite and your answer, I don't see the link with how to retrieve items selected by the user. – Thomas Jun 14 '13 at 14:25
@Thomas, click on the hyperlink text of "Take a look at this answer to help"... the coloring is a poor choice and almost looks identical to normal text. – DRapp Jun 14 '13 at 14:33

WPF - Bind a Control to a property

2 Answers2

EDIT for SelectedItems