WPF DataTemplate Performance

Question

Well, the problem is that if you have one DataTemplate for an object type, every time an object is present, a DataTemplate will be created that sounds right.

My problem is that our DataTemplate is very heavy and the application can have about 1000 objects using this DataTemplate.

I created a simplified example in which I created 5 Person objects and bind them to a ListView. The DataTemplate for the Person object is a Grid with a label and ContextMenu with 2 MenuItems. For simplicity, I just want to focus on MenuItems. Using the memory profiler, I see that there are only 10 MenuItem objects (2 per person, 5 people * 2 MenuItem = 10 MenuItem), and I want to know if there is a way to avoid this. Let's say each Person object must use the same MenuItem link to avoid duplicating a DataTemplate every time a person is created.

These are the results in the memory profiler.

Thank!

This is my code:

WITH#

using System.Collections.Generic;
using System.Windows;

namespace MenuItemsTest
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            this.DataContext = new List<Person>()
            {
                new Person("Jim Morrison"),
                new Person("Jimmy Page"),
                new Person("Jimmy Hendrix"),
                new Person("Janis Joplin"),
                new Person("Peter Frampton")
            };
        }
    }

    public class Person
    {
        public string Name { get; set; }

        public Person(string name)
        {
            this.Name = name;
        }
    }
}

XAML:

<Window x:Class="MenuItemsTest.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:MenuItemsTest"
    Title="Window1" Height="300" Width="300">
    <Window.Resources>
        <DataTemplate DataType="{x:Type local:Person}">
            <Grid>
                <Grid.ContextMenu>
                    <ContextMenu>
                        <MenuItem Header="Select" />
                        <MenuItem Header="Deselect" />
                    </ContextMenu>
                </Grid.ContextMenu>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>
                <Label Content="{Binding Name}" />
            </Grid>
        </DataTemplate>
    </Window.Resources>
    <Grid>
        <ListView ItemsSource="{Binding}" />
    </Grid>
</Window>

Answer 1

DataTemplates - , , , , 20 :

. , ListBox. = > .

, ListView (.. ), , .

  <ListView 
     ScrollViewer.HorizontalScrollBarVisibility="Disabled"
     ScrollViewer.VerticalScrollBarVisibility="Auto"
     VirtualizingStackPanel.IsVirtualizing="True"
     VirtualizingStackPanel.VirtualizationMode="Standard" 
     ItemsSource="{Binding}"
     />