DataGridRow Template Add row Slower

bonjour draco951
Le probleme est que les "containers" des items (customises generalement dans un datatemplate) sont traites d'un "seul coup" par le Thread de Rendu (hidden Render Thread auquel nous n'avons pas acces dans l'api) et non par le Thread UI...
Ceci peut etre observe si tu applique le style suivant à un DataGridRow sans passer par le Dispatcher :

Code:

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<Style 
            x:Key="StyleDataGridRow"
            TargetType="{x:Type DataGridRow}">
            <Setter Property="Background" Value="Transparent"/>
            <Setter Property="MaxHeight" Value="0"/>
            <Style.Triggers>
                <EventTrigger RoutedEvent="DataGridRow.Loaded">
                    <EventTrigger.Actions>
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation
                                  Duration="0:0:0.50"
                                  Storyboard.TargetProperty="MaxHeight"
                                  To="60"  
                                SpeedRatio="0.005"/>
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger.Actions>
                </EventTrigger>
            </Style.Triggers>
        </Style>

Le seul moyen pour contourner ce probleme c'est de passer par le Dispatcher d'Application et de charger les "workitems" comme dans un LongTaskRunning.
Ceci permet de mettre "en queue" les items et les envoyer au thread UI qui appellera le "thread de rendu" pour les afficher...avec un thread.sleep
Le code du class data utilise :

Code:

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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;
using System.Collections.ObjectModel;
 
namespace WinItemsRenderThread
{
    public class MyPerson : INotifyPropertyChanged
    {
        public MyPerson()
        {
            FName = string.Empty;
            LName = string.Empty;
 
        }
        public MyPerson(string fn, string ln):base()
        {
            FName = fn;
            LName = ln;
 
        }
        private string fname;
        public string FName
        {
            get { return fname; }
            set
            {
                fname = value; OnPropertyChanged("FName");
            }
        }
        private string lnamer;
        public string LName
        {
            get { return lnamer; }
            set
            {
                lnamer = value; OnPropertyChanged("LName");
            }
        }
 
        public event PropertyChangedEventHandler PropertyChanged;
        private void OnPropertyChanged(string np)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(np));
            }
 
        }
    }
    public class MyPersons : ObservableCollection<MyPerson>
    {
        private MyPerson p;
        public MyPersons()
        {
 
            for (int i = 1; i < 999; i++)
            {
                p = new MyPerson("FNAME" + i.ToString(), "LNAME" + i.ToString());
                this.Add(p);
            }
        }
 
    }
}

code xaml du winform:

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<Window x:Class="WinItemsRenderThread.WinLoadDGV"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WinItemsRenderThread"
        Title="WinLoadDGV" Height="300" Width="300">
    <Window.Resources>
 
        <Style
            x:Key="styleTB"
            TargetType="TextBlock">
            <Setter Property="Foreground" Value="Transparent"/>
            <Setter Property="Background" Value="Transparent"/>
            <Style.Triggers>
                <EventTrigger RoutedEvent="Loaded">
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation 
                                Storyboard.TargetProperty="(TextBlock.Background).(SolidColorBrush.Color)" 
                                Duration="00:00:03" 
                                From="Red" To="Transparent" />
                        </Storyboard>
                    </BeginStoryboard>
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation 
                                Storyboard.TargetProperty="(TextBlock.Foreground).(SolidColorBrush.Color)" 
                                Duration="00:00:03" 
                                From="Transparent" To="DarkBlue"  />
                        </Storyboard>
                    </BeginStoryboard>
                </EventTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <StackPanel>
        <StackPanel
        Orientation="Horizontal">
            <Button Content="Start"  
            Click="startButton_Click"
            Name="startButton"
            Margin="5,0,5,0"
            />
            <TextBlock 
                Margin="10,5,0,0"
                Text ="Item Added :  ">
            </TextBlock >
            <TextBlock 
                Name="tbNextItem" 
                Margin="4,5,0,0"
                Text="0">
            </TextBlock>
        </StackPanel>
        <DataGrid 
            x:Name="dgv"
            VirtualizingStackPanel.VirtualizationMode="Standard"
            AutoGenerateColumns="False"
            ItemsSource="{Binding}" 
            >
            <DataGrid.Columns>
                <DataGridTextColumn
                        Header="FirstName" 
                        Binding="{Binding FName}"
                       />
                <DataGridTextColumn 
                        Header="Last Name" 
                        Binding="{Binding LName}"
                        ElementStyle="{StaticResource styleTB}"/>
            </DataGrid.Columns>
        </DataGrid>
    </StackPanel>
</Window>

code .cs du winform (avec delegate):

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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.Windows.Threading;
using System.Threading;
 
namespace WinItemsRenderThread
{
    /// <summary>
    /// Logique d'interaction pour WinLoadDGV.xaml
    /// </summary>
    public partial class WinLoadDGV : Window
    {
        public delegate void NextItemDelegate();
 
        //Current number to check  
        private int num = 0;
 
        MyPersons MyList = new MyPersons();
        public WinLoadDGV()
        {
            InitializeComponent();
 
        }
        private void startButton_Click(object sender, RoutedEventArgs e)
        {
 
                this.dgv.Items.Clear();
                num = 0;
                startButton.Dispatcher.BeginInvoke(
                    DispatcherPriority.Normal,
                    new NextItemDelegate(LoadNextItem));
        }
        public void LoadNextItem()
        {
            MyPerson p = MyList[num];
            this.dgv.Items.Add(p);
 
 
            this.tbNextItem.Text = num.ToString() + " " + p.FName;
 
            num += 1;
            if (num < MyList.Count)
            {
 
                this.startButton.Dispatcher.BeginInvoke(
                       DispatcherPriority.Background,
                       new NextItemDelegate(this.LoadNextItem));
                Thread.Sleep(250);
            }
 
        }
 
 
    }
}

qui j'espere fera ton bonheur...
bon code....