# Binding to a collection of PropertyDefinitions | WPF Controls | DevExpress Documentation When engineering a WPF application using the MVVM architectural pattern, you may be required to describe [property](/WPF/15521/controls-and-libraries/property-grid/property-definitions) and [collection](/WPF/15719/controls-and-libraries/property-grid/property-definitions/collection-definitions) definitions in a Model or ViewModel. The [PropertyGridControl](/WPF/DevExpress.Xpf.PropertyGrid.PropertyGridControl) can automatically retrieve settings for property and collection definitions from a Model or ViewModel. [View Example: Generate Properties From a View Model Collection](https://github.com/DevExpress-Examples/wpf-property-grid-generate-properties-from-view-model-collection) ## View Model Implementation Assume a View Model. It includes the following classes. - *ViewModel* - the View Model. The View Model exposes the **EditObject** that will be edited within the PropertyGrid, and a set of properties of the edit object (via the **Properties** property). - *Employee* - a data object that contains employee information (e.g., first and last names, job position, etc.). - *Property* - describes a property (or collection) definition at the View Model level. This class provides properties that correspond to property definition settings. - C#

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;

namespace WpfApplication1 {
    public class ViewModel {
        public ViewModel() {
            EditObject = new Employee() {
                FirstName = "John",
                LastName = "Smith",
                Position = "Senior Developer",
                BirthDate = new DateTime(1987, 12, 15),
                PreviousPositions = new Positions() { "Junior Developer", "Middle Developer" }
            };
            Properties = new ObservableCollection<Property>();
            Properties.Add(new Property() { Name = "FirstName" });
            Properties.Add(new Property() { Name = "LastName" });
            Properties.Add(new Property() { Name = "Position" });
            Properties.Add(new Property() { Name = "BirthDate" });
            Properties.Add(new Property() { CollectionName = "PreviousPositions" });
        }

        public Employee EditObject { get; set; }
        public ObservableCollection<Property> Properties { get; set; }
    }

    public class Property {
        public string CollectionName { get; set; }
        public string Name { get; set; }
    }

    public class Employee {
        public DateTime BirthDate { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Position { get; set; }
        public Positions PreviousPositions { get; set; }
    }

    public class Positions : List<string> {
    }
}

Note If the **Properties** collection might be changed after it has been assigned to the **PropertyGrid** control, it should implement [INotifyCollectionChanged](https://learn.microsoft.com/dotnet/api/system.collections.specialized.inotifycollectionchanged), so that changes made within a View Model are automatically reflected by the property grid. ## Property Definition Templates and Template Selector The [PropertyGridControl](/WPF/DevExpress.Xpf.PropertyGrid.PropertyGridControl) generates property (and collection) definitions based on property definition templates. To choose the required template based on the property definition settings, use the *template selector*. The code sample below demonstrates how to implement templates for property and collection definitions (see XAML: *PropertyTemplate* and *CollectionTemplate*) and how to implement a template selector (the *PropertyDefinitionTemplateSelector* class), that will select the required template for each property or collection definition. - XAML - C#

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:dxprg="http://schemas.devexpress.com/winfx/2008/xaml/propertygrid"
    xmlns:local="clr-namespace:WpfApplication1"
    Height="350"
    Width="525"
    Title="MainWindow">

    <Window.DataContext>
        <local:ViewModel />
    </Window.DataContext>

    <Window.Resources>
        <local:PropertyDefinitionTemplateSelector x:Key="PropertyDefinitionTemplateSelector"/>
        <DataTemplate x:Key="PropertyTemplate">
            <dxprg:PropertyDefinition Path="{Binding Name}" />
        </DataTemplate>
        <DataTemplate x:Key="CollectionTemplate">
            <dxprg:CollectionDefinition Path="{Binding CollectionName}" />
        </DataTemplate>
    </Window.Resources>
    <Grid>
        <dxprg:PropertyGridControl Name="propertyGrid"
            PropertyDefinitionsSource="{Binding Properties}"
            PropertyDefinitionTemplateSelector="{StaticResource PropertyDefinitionTemplateSelector}"
            SelectedObject="{Binding EditObject}"
            ShowProperties="WithPropertyDefinitions" ExpandCategoriesWhenSelectedObjectChanged="True"/>
    </Grid>
</Window>

using System.Windows;
using System.Windows.Controls;

namespace WpfApplication1 {
    // A template selector.
    public class PropertyDefinitionTemplateSelector : DataTemplateSelector {
        public override DataTemplate SelectTemplate(object item, DependencyObject container) {
            Property propDef = (Property)item;
            FrameworkElement element = (FrameworkElement)container;

            if(!string.IsNullOrEmpty(propDef.CollectionName)) {
                return element.TryFindResource("CollectionTemplate") as DataTemplate;
            }
            return element.TryFindResource("PropertyTemplate") as DataTemplate;
        }
    }
    // ...
}

Note If the **PropertyGrid** displays property definitions that can be described using a single template, you have no need to create a template selector. Instead, assign this template to the property grid’s [PropertyGridControl.PropertyDefinitionTemplate](/WPF/DevExpress.Xpf.PropertyGrid.PropertyGridControl.PropertyDefinitionTemplate) property. ## Binding PropertyGrid to ViewModel To bind the [PropertyGridControl](/WPF/DevExpress.Xpf.PropertyGrid.PropertyGridControl) to a ViewModel, specify the following properties. - The [PropertyGridControl.PropertyDefinitionsSource](/WPF/DevExpress.Xpf.PropertyGrid.PropertyGridControl.PropertyDefinitionsSource) property - to specify the PropertyGrid’s property source. - The [PropertyGridControl.PropertyDefinitionTemplate](/WPF/DevExpress.Xpf.PropertyGrid.PropertyGridControl.PropertyDefinitionTemplate) property - to specify the template used to convert objects from the PropertyGrid’s property source into property definitions. - The [PropertyGridControl.PropertyDefinitionTemplateSelector](/WPF/DevExpress.Xpf.PropertyGrid.PropertyGridControl.PropertyDefinitionTemplateSelector) property - to specify the property definition template selector that returns a template for each property definition based on its type. - The [PropertyGridControl.SelectedObject](/WPF/DevExpress.Xpf.PropertyGrid.PropertyGridControl.SelectedObject) property - to specify the edited object. - XAML

<Grid>
    <dxprg:PropertyGridControl Name="propertyGrid"
        PropertyDefinitionsSource="{Binding Properties}"
        PropertyDefinitionTemplateSelector="{StaticResource PropertyDefinitionTemplateSelector}"
        SelectedObject="{Binding EditObject}"
        ShowProperties="WithPropertyDefinitions" ExpandCategoriesWhenSelectedObjectChanged="True"/>
</Grid>

The image below illustrates the result. ![property_grid_mvvm.png](/WPF/images/property_grid_mvvm.png126460.png)