si utiliza el convertidor funciona por primera vez perfecto, pero si uno o más registros llegan a la lista de registro, no hay actualización en su enlace, porque el convertidor funciona solo la primera vez. ¡todos los controles que no son controles de elementos no se suscriben al evento listchanged!
aquí es un poco de código para este escenario
using System;
using System.Collections.ObjectModel;
using System.Windows;
namespace BindListToTextBlock
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
private WorkItem workItem;
public MainWindow() {
this.WorkItems = new ObservableCollection<WorkItem>();
this.DataContext = this;
this.InitializeComponent();
}
public class WorkItem
{
public WorkItem() {
this.Logs = new ObservableCollection<string>();
}
public string Name { get; set; }
public ObservableCollection<string> Logs { get; private set; }
}
public ObservableCollection<WorkItem> WorkItems { get; set; }
private void Button_Click(object sender, RoutedEventArgs e) {
this.workItem = new WorkItem() {Name = string.Format("new item at {0}", DateTime.Now)};
this.workItem.Logs.Add("first log");
this.WorkItems.Add(this.workItem);
}
private void Button_Click_1(object sender, RoutedEventArgs e) {
if (this.workItem != null) {
this.workItem.Logs.Add(string.Format("more log {0}", DateTime.Now));
}
}
}
}
la xaml
<Window x:Class="BindListToTextBlock.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:BindListToTextBlock="clr-namespace:BindListToTextBlock"
Title="MainWindow"
Height="350"
Width="525">
<Grid>
<Grid.Resources>
<BindListToTextBlock:ListToStringConverter x:Key="ListToStringConverter" />
</Grid.Resources>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition />
</Grid.RowDefinitions>
<Button Grid.Row="0"
Content="Add item..."
Click="Button_Click" />
<Button Grid.Row="1"
Content="Add some log to last item"
Click="Button_Click_1" />
<ListView Grid.Row="2"
ItemsSource="{Binding Path=WorkItems}">
<ListView.View>
<GridView>
<GridViewColumn Header="Name">
<GridViewColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=Name}" />
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
<GridViewColumn Header="Log Message">
<GridViewColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=Logs, Converter={StaticResource ListToStringConverter}}" />
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>
</Grid>
</Window>
el convertidor
using System;
using System.Collections;
using System.Globalization;
using System.Linq;
using System.Windows;
using System.Windows.Data;
namespace BindListToTextBlock
{
public class ListToStringConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture) {
if (value is IEnumerable) {
return string.Join(Environment.NewLine, ((IEnumerable)value).OfType<string>().ToArray());
}
return "no messages yet";
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) {
return DependencyProperty.UnsetValue;
}
}
}
EDITAR
aquí es una solución rápida para la actualización propblem (esto se puede también hacer con una propiedad adjunta)
public class CustomTextBlock : TextBlock, INotifyPropertyChanged
{
public static readonly DependencyProperty ListToBindProperty =
DependencyProperty.Register("ListToBind", typeof(IBindingList), typeof(CustomTextBlock), new PropertyMetadata(null, ListToBindPropertyChangedCallback));
private static void ListToBindPropertyChangedCallback(DependencyObject o, DependencyPropertyChangedEventArgs e)
{
var customTextBlock = o as CustomTextBlock;
if (customTextBlock != null && e.NewValue != e.OldValue) {
var oldList = e.OldValue as IBindingList;
if (oldList != null) {
oldList.ListChanged -= customTextBlock.BindingListChanged;
}
var newList = e.NewValue as IBindingList;
if (newList != null) {
newList.ListChanged += customTextBlock.BindingListChanged;
}
}
}
private void BindingListChanged(object sender, ListChangedEventArgs e)
{
this.RaisePropertyChanged("ListToBind");
}
public IBindingList ListToBind
{
get { return (IBindingList)this.GetValue(ListToBindProperty); }
set { this.SetValue(ListToBindProperty, value); }
}
private void RaisePropertyChanged(string propName)
{
var eh = this.PropertyChanged;
if (eh != null) {
eh(this, new PropertyChangedEventArgs(propName));
}
}
public event PropertyChangedEventHandler PropertyChanged;
}
aquí es el uso de la CustomTextBlock
(no probado)
<TextBlock Text="{Binding Path=ListToBind, RelativeSource=Self, Converter={StaticResource ListToStringConverter}}"
ListToBind={Binding Path=Logs} />
esperanza @Fueled este ayuda
Eso funcionó perfectamente gracias Jobi. – Joshua