绑定到用户控件WPF/XAML的依赖项属性

Question

我的应用程序如下所示:

---

SectionHeader

SectionHeader

内容

SectionHeader

内容

---

SectionHeader 是具有两个依赖项属性=标题和应用程序的用户控件.

标题不会更改,但应用程序需要绑定到主窗口视图模型Apps属性.只有三个部分标题中的两个需要Apps属性.

<c:SectionHeader DockPanel.Dock="Top" x:Name="SectionResources" Title="RESOURCES"
   Apps="{Binding Path=Apps}" />

这就是目前的情况.问题是应用程序没有出现.

在SectionHeaderDataContext中设置为自身如下,允许标题显示.

DataContext="{Binding RelativeSource={RelativeSource Self}}"

应用程序是ItemsControlUserControl中a的ItemsSource :

<ItemsControl
      ItemsSource="{Binding Apps}">

---

所以我的问题是:

• 我如何将数据绑定到UserControl DP？
• 在没有UserControls的情况下,这是一种更简单的方法吗？

编辑:

忘了提到Apps是AppsItems的ObservableCollection.

这就是我的DP的样子:

public static readonly DependencyProperty AppsProperty = DependencyProperty.Register("Apps",
  typeof (ObservableCollection<AppsItem>), typeof (SectionHeader),
  new PropertyMetadata(null, OnAppsPropertyChanged));

private static void OnAppsPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
  Console.WriteLine("Hello!!!");
  var sectionHeader = d as SectionHeader;
  var value = e.NewValue as ObservableCollection<AppsItem>;
  sectionHeader.Apps = value;
}

Answer 1

给你的usecontrol命名并尝试像这样绑定

ItemsSource="{Binding Apps,ElementName=root}"

和root是您的usercontrol的名称

  <UserControl x:Class="WpfApplication1.MainWindow"
            xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             Height="350" Width="525"
     x:Name="root">

它是具有Apps属性的用户控件的元素绑定

Answer 2

试图从你的描述中重新编写这个并遇到类似的问题后,我发现我能使其工作的唯一方法是不设置UserControl的DataContext,而是使用ElementBinding:

<UserControl x:Class="WpfApplication2.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             x:Name="thisUC"
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <Border Background="Red" Padding="10">
        <ListBox x:Name="ucList" ItemsSource="{Binding ElementName=thisUC, Path=UCApps}"/>
        </Border>

    </Grid>
</UserControl>

这个UC的实现非常简单:

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.Navigation;
using System.Windows.Shapes;
using System.Collections.ObjectModel;
using System.Collections;

namespace WpfApplication2
{
    /// <summary>
    /// Interaction logic for UserControl1.xaml
    /// </summary>
    public partial class UserControl1 : UserControl
    {
        public IEnumerable UCApps
        {
            get { return (IEnumerable)GetValue(UCAppsProperty); }
            set { SetValue(UCAppsProperty, value); }
        }

        // Using a DependencyProperty as the backing store for Apps.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty UCAppsProperty =
            DependencyProperty.Register("UCApps", typeof(IEnumerable), typeof(UserControl1), new UIPropertyMetadata(null));

        public UserControl1()
        {
            InitializeComponent();            
        }
    }
}

就像调用它的XAML一样:

<Grid >
    <my:UserControl1 x:Name="ucName" UCApps="{Binding Path=Apps}"/>
</Grid>

(我Apps在你的Usercontrol中更改了名称,UCApps以便我可以看到发生了什么 - 太多同名的属性令人困惑!)