Managing Collection Properties

• Jun 07, 2019
• 6 minutes to read

The Property Grid allows you to add, browse and edit collection properties.

Note

The code sample below illustrates how to add a new objects to collections using CollectionDefinition.NewItemInitializer property. To use this code sample in your project, reference the DevExpresss.Xpf.Grid and DevExpress.Xpf.Grid.Core assembly.

The PropertyGrid control supports adding new objects to collections using the collection editor. To pre-set certain properties for a new object or create an object without the default constructor, use the CollectionDefinition.NewItemInitializer property. Like PropertyDefinitionBase.InstanceInitializer, it should be set to an object that implements the DevExpress.Mvvm.Native.IInstanceInitializer interface.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-add-an-object-with-predefined-property-values-using-the-collection-editor-e4855.

Application.xaml

<Application x:Class="pgrid_collection.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             StartupUri="MainWindow.xaml">
    <Application.Resources>

    </Application.Resources>
</Application>

MainWindow.xaml

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:pgrid_collection"
        xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
        xmlns:dxprg="http://schemas.devexpress.com/winfx/2008/xaml/propertygrid" 
        xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid" 
        x:Class="pgrid_collection.MainWindow"
        Title="MainWindow" Height="500" Width="1000">

    <Window.Resources>
        <ResourceDictionary>
            <local:ItemInitializer x:Key="itemInitializer" />
        </ResourceDictionary>
    </Window.Resources>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition />
            <ColumnDefinition Width="400" />
        </Grid.ColumnDefinitions>
        <dxprg:PropertyGridControl Name="pGrid" SelectedObject="{Binding Path=CurrentItem, ElementName=grid}" Grid.Column="1" UseCollectionEditor="{x:Null}"
                                   ShowProperties="WithPropertyDefinitions" ShowCategories="False" CellValueChanged="pGrid_CellValueChanged" >
            <dxprg:PropertyDefinition Path="ProductName" />
            <dxprg:PropertyDefinition Path="City" />
            <dxprg:PropertyDefinition Path="Country" />
            <dxprg:PropertyDefinition Path="UnitPrice" />
            <dxprg:PropertyDefinition Path="Quantity" />
            <dxprg:CollectionDefinition Path="Suppliers" Type="{x:Type local:SupplierBase}"
                                        NewItemInitializer="{StaticResource itemInitializer}" UseCollectionEditor="True" >
                <dxprg:PropertyDefinition Path="*.FirstName" />
                <dxprg:PropertyDefinition Path="*.LastName" />
                <dxprg:PropertyDefinition Path="*.Phone" />
            </dxprg:CollectionDefinition>
        </dxprg:PropertyGridControl>
        <dxg:GridControl Name="grid" Grid.Column="0">
            <dxg:GridControl.Columns>
                <dxg:GridColumn FieldName="ProductName" />
                <dxg:GridColumn FieldName="Country" />
                <dxg:GridColumn FieldName="City" />
                <dxg:GridColumn FieldName="UnitPrice" />
                <dxg:GridColumn FieldName="Quantity" />
            </dxg:GridControl.Columns>
            <dxg:GridControl.View>
                <dxg:TableView AllowEditing="False" />
            </dxg:GridControl.View>
        </dxg:GridControl>



    </Grid>
</Window>

Application.xaml.vb

Imports System
Imports System.Collections.Generic
Imports System.Configuration
Imports System.Data
Imports System.Linq
Imports System.Threading.Tasks
Imports System.Windows

Namespace pgrid_collection
    Partial Public Class App
        Inherits Application

    End Class
End Namespace

Products.vb

Imports System.Collections.Generic

Namespace pgrid_collection

    Public Class Supplier
        Public Property FirstName() As String
        Public Property LastName() As String
        Public Property Phone() As String
    End Class

    Public Class SupplierBase
        Inherits List(Of Supplier)

        Public Sub New()
            MyBase.New()
        End Sub
    End Class

    Public Class Product
        Public Property ProductName() As String
        Public Property Country() As String
        Public Property City() As String
        Public Property UnitPrice() As Double
        Public Property Quantity() As Integer
        Public Property Suppliers() As SupplierBase
    End Class

    Public Class ProductList
        Inherits List(Of Product)

        Public Sub New()
            MyBase.New()
            Add(New Product() With { _
                .ProductName = "Chang", _
                .Country = "UK", _
                .City = "Cowes", _
                .UnitPrice = 19, _
                .Quantity = 10, _
                .Suppliers = New SupplierBase() _
            })
            Add(New Product() With { _
                .ProductName = "Gravad lax", _
                .Country = "Italy", _
                .City = "Reggio Emilia", _
                .UnitPrice = 12.5, _
                .Quantity = 16, _
                .Suppliers = New SupplierBase() _
            })
            Add(New Product() With { _
                .ProductName = "Ravioli Angelo", _
                .Country = "Brazil", _
                .City = "Rio de Janeiro", _
                .UnitPrice = 19, _
                .Quantity = 12, _
                .Suppliers = New SupplierBase() _
            })
            Add(New Product() With { _
                .ProductName = "Tarte au sucre", _
                .Country = "Germany", _
                .City = "QUICK-Stop", _
                .UnitPrice = 22, _
                .Quantity = 50, _
                .Suppliers = New SupplierBase() _
            })
            Add(New Product() With { _
                .ProductName = "Steeleye Stout", _
                .Country = "USA", _
                .City = "Reggio Emilia", _
                .UnitPrice = 18, _
                .Quantity = 20, _
                .Suppliers = New SupplierBase() _
            })
            Add(New Product() With { _
                .ProductName = "Pavlova", _
                .Country = "Austria", _
                .City = "Graz", _
                .UnitPrice = 21, _
                .Quantity = 52, _
                .Suppliers = New SupplierBase() _
            })
            Add(New Product() With { _
                .ProductName = "Longlife Tofu", _
                .Country = "USA", _
                .City = "Boise", _
                .UnitPrice = 7.75, _
                .Quantity = 120, _
                .Suppliers = New SupplierBase() _
            })
            Add(New Product() With { _
                .ProductName = "Alice Mutton", _
                .Country = "Canada", _
                .City = "Tsawwassen", _
                .UnitPrice = 44, _
                .Quantity = 16, _
                .Suppliers = New SupplierBase() _
            })
        End Sub
    End Class
End Namespace

MainWindow.xaml.vb

Imports System.Collections.Generic
Imports System.Windows
Imports DevExpress.Mvvm.Native
Imports DevExpress.Xpf.PropertyGrid

Namespace pgrid_collection

    Partial Public Class MainWindow
        Inherits Window

        Public Sub New()
            InitializeComponent()
            grid.ItemsSource = New ProductList()
        End Sub

        Private Sub pGrid_CellValueChanged(ByVal sender As Object, ByVal args As DevExpress.Xpf.PropertyGrid.CellValueChangedEventArgs)
            Dim rowhandle = grid.GetSelectedRowHandles()(0)
            grid.RefreshRow(rowhandle)
        End Sub
    End Class
    Public Class ItemInitializer
        Implements IInstanceInitializer

        Public Sub New()
        End Sub

        Private Function IInstanceInitializer_CreateInstance(ByVal type As TypeInfo) As Object Implements IInstanceInitializer.CreateInstance
            Dim item = New Supplier()
            item.FirstName = "FIRSTNAME"
            item.LastName = "LASTNAME"
            item.Phone = "PHONE"
            Return item
        End Function


        Private ReadOnly Property IInstanceInitializer_Types() As IEnumerable(Of TypeInfo) Implements IInstanceInitializer.Types
            Get
                Return New List(Of TypeInfo)() From {New TypeInfo(GetType(Supplier), "New Supplier")}
            End Get
        End Property
    End Class
End Namespace

MainWindow.xaml.cs

using System.Collections.Generic;
using System.Windows;
using DevExpress.Mvvm.Native;
using DevExpress.Xpf.PropertyGrid;

namespace pgrid_collection {

    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
            grid.ItemsSource = new ProductList();
        }

        private void pGrid_CellValueChanged(object sender, DevExpress.Xpf.PropertyGrid.CellValueChangedEventArgs args) {
            var rowhandle = grid.GetSelectedRowHandles()[0];
            grid.RefreshRow(rowhandle);
        }
    }
    public class ItemInitializer : IInstanceInitializer {
        public ItemInitializer() {
        }

        object IInstanceInitializer.CreateInstance(TypeInfo type) {
            var item = new Supplier();
            item.FirstName = "FIRSTNAME";
            item.LastName = "LASTNAME";
            item.Phone = "PHONE";
            return item;
        }


        IEnumerable<TypeInfo> IInstanceInitializer.Types {
            get {
                return new List<TypeInfo>() {
                        new TypeInfo(typeof(Supplier), "New Supplier"),
                    };
            }
        }
    }
}

Products.cs

using System.Collections.Generic;

namespace pgrid_collection {

    public class Supplier {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Phone { get; set; }
    }

    public class SupplierBase : List<Supplier> {
        public SupplierBase()
            : base() {
        }
    }

    public class Product {
        public string ProductName { get; set; }
        public string Country { get; set; }
        public string City { get; set; }
        public double UnitPrice { get; set; }
        public int Quantity { get; set; }
        public SupplierBase Suppliers { get; set; }
    }

    public class ProductList : List<Product> {
        public ProductList()
            : base() {
            Add(new Product() { ProductName = "Chang", Country = "UK", City = "Cowes", UnitPrice = 19, Quantity = 10, Suppliers = new SupplierBase() });
            Add(new Product() { ProductName = "Gravad lax", Country = "Italy", City = "Reggio Emilia", UnitPrice = 12.5, Quantity = 16, Suppliers = new SupplierBase() });
            Add(new Product() { ProductName = "Ravioli Angelo", Country = "Brazil", City = "Rio de Janeiro", UnitPrice = 19, Quantity = 12, Suppliers = new SupplierBase() });
            Add(new Product() { ProductName = "Tarte au sucre", Country = "Germany", City = "QUICK-Stop", UnitPrice = 22, Quantity = 50, Suppliers = new SupplierBase() });
            Add(new Product() { ProductName = "Steeleye Stout", Country = "USA", City = "Reggio Emilia", UnitPrice = 18, Quantity = 20, Suppliers = new SupplierBase() });
            Add(new Product() { ProductName = "Pavlova", Country = "Austria", City = "Graz", UnitPrice = 21, Quantity = 52, Suppliers = new SupplierBase() });
            Add(new Product() { ProductName = "Longlife Tofu", Country = "USA", City = "Boise", UnitPrice = 7.75, Quantity = 120, Suppliers = new SupplierBase() });
            Add(new Product() { ProductName = "Alice Mutton", Country = "Canada", City = "Tsawwassen", UnitPrice = 44, Quantity = 16, Suppliers = new SupplierBase() });
        }
    }
}