WPF Datagrid: при загрузке, выбор текущего элемента (выделение)

при использовании модели в качестве DataContext для окна WPF DataGrid SelectionChanged событие не вызывается до тех пор, пока окно не будет загружено, поэтому строка никогда не выделяется, и вы видите только первую строку с частичной подсветкой. Возможно, есть более элегантный способ, но вот обходной путь.

в событии loaded окна или событии loaded DataGrid сбросьте привязку SelectedItem:

public MainWindow()
{
    InitializeComponent(); 
    this.Loaded += new RoutedEventHandler( OnLoaded );
}

// could also be placed in the DataGrid's loaded event handler
private void OnLoaded( object sender, RoutedEventArgs e )
{
    if( dataGrid != null && Model.SelectedItem != null )
    {
        var selected = Model.SelectedItem;
        Model.SelectedItem = null;
        Model.SelectedItem = selected;
    }
}

вот полная работа образец.

XAML

<Window x:Class="WpfDataGridHighlightOnLoad.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:model="clr-namespace:WpfDataGridHighlightOnLoad" 
        Title="MainWindow" Height="350" Width="525">

    <Window.DataContext>
        <model:MainWindowModel x:Name="Model" />
    </Window.DataContext>

    <Grid>
        <DataGrid AutoGenerateColumns="True" SelectionMode="Single"
                  HorizontalAlignment="Stretch" 
                  Name="dataGrid" 
                  VerticalAlignment="Top"
                  ItemsSource="{Binding ItemList}"
                  SelectedItem="{Binding SelectedItem}">
        </DataGrid>

        <Button Content="Cycle Selection" Click="OnCycleClick" 
                Height="23" 
                HorizontalAlignment="Right" 
                Name="button1" 
                VerticalAlignment="Bottom" Width="125" />

        <Button Content="Reset Grid" Click="OnResetClick" 
                Height="23" 
                HorizontalAlignment="Left" 
                Name="button2" 
                VerticalAlignment="Bottom" Width="125" />

    </Grid>
</Window>

Код

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

namespace WpfDataGridHighlightOnLoad
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();   
            this.Loaded += new RoutedEventHandler( OnLoaded );
        }

        // could also be placed in the DataGrid's loaded event handler
        private void OnLoaded( object sender, RoutedEventArgs e )
        {
            if( dataGrid != null && Model.SelectedItem != null )
            {
                var selected = Model.SelectedItem;
                Model.SelectedItem = null;
                Model.SelectedItem = selected;
            }
        }

        private void OnCycleClick( object sender, RoutedEventArgs e )
        {
            int index = Model.ItemList.IndexOf( Model.SelectedItem );
            index = index == Model.ItemList.Count - 1 ? 0 : index + 1;
            Model.SelectedItem = Model.ItemList[index];
        }

        private void OnResetClick( object sender, RoutedEventArgs e )
        {
            Model.Reset();
        }
    }

    public class MainWindowModel : INotifyPropertyChanged
    {
        public MainWindowModel()
        {
            Reset();
        }

        public void Reset()
        {
            ItemList = new List<Person>
                           {
                               new Person("Joe", 20),
                               new Person("John", 30),
                               new Person("Jane", 40),
                               new Person("Jill", 50),
                               new Person("Fido", 7),
                           };

            SelectedItem = ItemList[2];
        }

        private Person _selectedItem;
        public Person SelectedItem
        {
            get { return _selectedItem; }
            set
            {
                _selectedItem = value;
                NotifyPropertyChanged( "SelectedItem" );
            }
        }

        private List<Person> _itemList;
        public List<Person> ItemList
        {
            get { return _itemList; }
            set
            {
                _itemList = value;
                NotifyPropertyChanged( "ItemList" );
            }
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged( String info )
        {
            if( PropertyChanged != null )
            {
                PropertyChanged( this, new PropertyChangedEventArgs( info ) );
            }
        }

        #endregion
    }

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

        public Person( string name, int age )
        {
            Name = name;
            Age = age;
        }

        public override string ToString()
        {
            return Name;
        }
    }
}