TreeView - Selectionner dynamiquement au démarrage de la fenêtre le premier node

Version imprimable

Bonjour,

Je coince ....

J'ai un TreeView qui affiche deux niveaux (une liste d'objet A, et ces objets A ont une propriété qui contient une liste d'objets B).

Code:

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 <TreeView  ScrollViewer.VerticalScrollBarVisibility="Visible" ItemsSource="{Binding A}" Height="338" Width="190" >
                        <TreeView.ItemTemplate>
                            <DataTemplate>
                                <TreeViewItem ItemsSource="{Binding B}" Header="{Binding Name}" FontWeight="Bold">
                                    <TreeViewItem.ItemTemplate>
                                        <DataTemplate>
                                            <DockPanel>
 
                                                <Image Margin="-10 0" RenderOptions.BitmapScalingMode="HighQuality" Visibility="{Binding Path=ReadOnly, Converter={StaticResource BooleanToVisibilityConverter}}" Height="12" Width="9" Source=".\Icons\Locked.png" />
                                                <ToggleButton 
                                                    Margin="5 0" 
                                                    Foreground="#FF483737"
                                                    FontWeight="{Binding Path=ReadOnly, Converter={StaticResource BooleanToFontWeigthConverter}}"
                                                    Background="Transparent" BorderThickness="0" Content="{Binding Name}" Click="Select"/>
 
                                            </DockPanel>
                                        </DataTemplate>
                                    </TreeViewItem.ItemTemplate>
                                </TreeViewItem>
                            </DataTemplate>
                        </TreeView.ItemTemplate>
                    </TreeView>

Code:

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namespace TrainDEController
{
    public partial class ExerciseWindow : Window
    {
        public List<A> Groups { get; private set; }
        public B Selected  { get; private set; }
 
        public ExerciseWindow(User user)
        {
           Groups = RandomDatas.CreateRandomGroups();
            InitializeComponent();
        }
 
        private void Select(object sender, RoutedEventArgs e)
        {
 
        }
 
    }
}

Je souhaiterais à l'affichage du treeview automatiquement placer le focus (ou sélectionner) le premier node de l'objet B du premier node de l'objet A.
J’espère être clair. Merci pour votre aide ...

Bonjour

Le Treeview Wpf doit dirigé par les données en coulisses ...

Exemple code...

1/class data exemple :

Code:

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namespace WpfTreeNode
{
    public class BaseNode:INotifyPropertyChanged 
    {
        private bool isExpanded;
        public bool IsExpanded 
        {
            get { return isExpanded; }
            set
            {
                if (value != isExpanded)
                {
                    isExpanded = value;
                    OnPropertyChanged("IsExpanded");
                }
            }
        }
        private bool isSelected;
        public bool IsSelected
        {
            get { return isSelected; }
            set
            {
                if (value != isSelected)
                {
                    isSelected = value;
                    OnPropertyChanged("IsSelected");
                }
            }
        }
 
 
 
        public event PropertyChangedEventHandler PropertyChanged;
        public void OnPropertyChanged(string propname)
        {
            PropertyChangedEventHandler h = PropertyChanged;
            if (h != null)
                h(this, new PropertyChangedEventArgs(propname));
        }
    }
 
 
 
    public class ItemB:BaseNode
    {
        private string  header;
        public string Header
        {
            get { return header; }
            set
            {
                header = value; 
                OnPropertyChanged("Header");
 
            }
        }
 
        public ItemB()
            : base()
        {
        }
    }
 
public class ItemA:BaseNode
    {
        private string header;
        public string Header
        {
            get { return header; }
            set
            {
                header = value; OnPropertyChanged("Header");
 
            }
        }
        private ObservableCollection<ItemB> children;
        public ObservableCollection<ItemB>  Children
        {
            get { return children; }
            set
            {
                children = value;
                OnPropertyChanged("Children");
 
            }
        }
        public ItemA():base()
        {
            children = new ObservableCollection<ItemB>();
        }
    }
 
 
 
}

2/ form user exemple

code xaml du form user:

Code:

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<Window x:Class="WpfTreeNode.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
       xmlns:local="clr-namespace:WpfTreeNode"
        Title="MainWindow" Height="350" Width="525">
    <Window.DataContext>
        <local:ListItems/>
    </Window.DataContext>
    <Window.Resources>
        <HierarchicalDataTemplate DataType="{x:Type local:ItemA}"
                                  ItemsSource="{Binding Children}">
            <StackPanel Orientation="Horizontal">
                <TextBlock Margin="5" Text="{Binding Header}"/>
            </StackPanel>
        </HierarchicalDataTemplate>
        <DataTemplate DataType="{x:Type local:ItemB}">
            <StackPanel Orientation="Horizontal">
                <TextBlock Margin="5" Text="{Binding Header}"/>
            </StackPanel>
        </DataTemplate>
    </Window.Resources>
    <Grid>
        <TreeView
            x:Name="tv"
            >
            <TreeViewItem
               Header="Groups"
                IsExpanded="True"
                ItemsSource="{Binding }">
                <TreeViewItem.ItemContainerStyle>
                    <Style TargetType="TreeViewItem">
                        <Setter Property="IsExpanded" Value="{Binding IsExpanded}" />
                        <Setter Property="IsSelected" Value="{Binding IsSelected}"/>
                        <Style.Triggers>
                            <Trigger Property="IsSelected" Value="true">
                                <Setter Property="Background" Value="Red"/>
                            </Trigger>
                        </Style.Triggers>
                    </Style>
                </TreeViewItem.ItemContainerStyle>
            </TreeViewItem>
        </TreeView>
    </Grid>
</Window>

code behind.cs du form user:

Code:

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namespace WpfTreeNode
{
    /// <summary>
    /// Logique d'interaction pour MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private ListItems groups = null;
        public MainWindow()
        {
            InitializeComponent();
            this.Loaded += new RoutedEventHandler(MainWindow_Loaded);
        }
        void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            groups = this.DataContext as ListItems;
 
            groups[0].IsExpanded = true;
            groups[0].Children[0].IsSelected = true;
        }
    }
}

bon code...

25/09/2019, 16h18
LaurentC33
Bonjour et merci Mabrouki ;)

Effectivement, je suis sorti du pattern MVVM et forcement...
En suivant ton modèle ça fonctionne proprement et simplement en faisant :
Code:

1 2 _exercisesViewModel.A.First().B.First().IsSelected = true;
Super ce pattern :)

Merci encore à toi ;)