我没有运气尝试将数据集合绑定到我的自定义控件的属性。我已经实现了该控件的字符串属性的机制(在此处提供了一些帮助),并期望集合类型同样简单。但是我无法让它再次工作。
这是我的自定义控件视图
<UserControl x:Class="BadaniaOperacyjne.Controls.Matrix"
mc:Ignorable="d" Name="CustomMatrix"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<Grid.RowDefinitions>
<!-- ... -->
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<!-- ... -->
</Grid.ColumnDefinitions>
<TextBlock Grid.Row="0" Grid.Column="1" Text="{Binding ElementName=CustomMatrix, Path=Title}"/>
<Grid Grid.Row="2" Grid.Column="1" Name="contentGrid">
<ListBox ItemsSource="{Binding ElementName=CustomMatrix, Path=ItemsList}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Grid>
</UserControl>
及其隐藏代码
#region ItemsList Property
public static readonly DependencyProperty ItemsListProperty =
DependencyProperty.Register("ItemsList", typeof(ObservableCollection<object>), typeof(Matrix), new PropertyMetadata(new ObservableCollection<object>(), new PropertyChangedCallback(ItemsListChanged)));
public ObservableCollection<object> ItemsList
{
get { return GetValue(ItemsListProperty) as ObservableCollection<object>; }
set { SetValue(ItemsListProperty, value); }
}
private void ItemsListChanged(object value)
{
System.Diagnostics.Debug.WriteLine("matrix: items list changed " + value);
if (ItemsList != null)
{
ItemsList.CollectionChanged += ItemsList_CollectionChanged;
System.Diagnostics.Debug.WriteLine("got " + string.Join(",", ItemsList.ToList()));
}
else
{
System.Diagnostics.Debug.WriteLine("got null");
}
}
void ItemsList_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
System.Diagnostics.Debug.WriteLine("matrix: current items list collection changed");
}
private static void ItemsListChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
// a breakpoint
((Matrix)d).ItemsListChanged(e.NewValue);
}
#endregion
// showing the Title property implementation just to state that
// it is done the same way as for ItemsList
#region Title Property
public static readonly DependencyProperty TitleProperty =
DependencyProperty.Register("Title", typeof(string), typeof(Matrix), new PropertyMetadata("", new PropertyChangedCallback(TitleChanged)));
public string Title
{
get { return (string)GetValue(TitleProperty); }
set { SetValue(TitleProperty, value); }
}
private void TitleChanged(string title)
{
System.Diagnostics.Debug.WriteLine("matrix: title changed to: " + title);
}
private static void TitleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((Matrix)d).TitleChanged((string)e.NewValue);
}
#endregion
这就是我尝试绑定到该控件的方式
<custom:Matrix x:Name="customMatrix" DockPanel.Dock="Top" Title="{Binding Title}" ItemsList="{Binding Items}"/>
主页的代码隐藏是
//internal ObservableCollection<List<int>> ItemsList { get; set; }
public class ViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public ViewModel()
{
Items = new ObservableCollection<int> { 1, 2, 3, 4, 5, 6};
}
void Items_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
System.Diagnostics.Debug.WriteLine("problem manager: items list changed " + e.NewItems.Count);
}
public ObservableCollection<int> Items { get; set; }
protected string title;
public string Title
{
get { return title; }
set
{
if (title != value)
{
title = value;
NotifyPropertyChanged("Title");
}
}
}
protected void NotifyPropertyChanged(string name)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(name));
}
}
}
public ViewModel VM { get; private set; }
// this is the window constructor
private ProblemManager()
{
VM = new ViewModel();
DataContext = VM;
InitializeComponent();
VM.Title = "title";
}
private int i = 0;
private void btnAddRow_Click(object sender, RoutedEventArgs e)
{
// when doing either of these two lines below,
// the control breakpoint is never hit
VM.Items.Add(++i);
VM.Items = new ObservableCollection<int> { 2, 3 };
// however, when directly assigning to the control's property,
// the event is raised and the breakpoint is hit and the UI is updated
customMatrix.ItemsList = new ObservableCollection<object> { 1, 2, 3 };
customMatrix.ItemsList.Add(66);
// and this of course makes the control's title update
VM.Title = (++i).ToString();
}
Both DependencyProperty
s 为控件的Title
and ItemsList
我相信,它们都是以同样的方式创建的。尽管如此,绑定可能无法正常工作ItemsListChanged
该绑定不会引发事件。
所以,问题是我无法绑定我的窗口ViewModel.Items
通过 XAML 收集到控件的ItemsList
收藏。正在创建一个DependencyProperty
对于控件内的集合,任何不同于DependencyProperty
对于一个简单的string
财产?