Wpf 绑定用户控件中的ObservableCollection依赖项属性
我有一个UserControl,它托管一个TreeView,该TreeView有一个从自定义类的ObservableCollection继承的自定义集合。我试图使用ViewModel中的依赖项属性绑定到一个属性,但我已经证明该过程适用于另一个属性,但在这里它不起作用 我肯定我错过了一些愚蠢的事情,但我一直在兜圈子,有人能发现我的错误吗 UserControl XAML:Wpf 绑定用户控件中的ObservableCollection依赖项属性,wpf,user-controls,treeview,observablecollection,dependency-properties,Wpf,User Controls,Treeview,Observablecollection,Dependency Properties,我有一个UserControl,它托管一个TreeView,该TreeView有一个从自定义类的ObservableCollection继承的自定义集合。我试图使用ViewModel中的依赖项属性绑定到一个属性,但我已经证明该过程适用于另一个属性,但在这里它不起作用 我肯定我错过了一些愚蠢的事情,但我一直在兜圈子,有人能发现我的错误吗 UserControl XAML: <UserControl x:Class="FileExplorer.TreeViewUserControl" xmln
<UserControl
x:Class="FileExplorer.TreeViewUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:fe="clr-namespace:WpfControlLibrary.FileExplorer"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
x:Name="FileExplorer"
d:DesignHeight="300"
d:DesignWidth="400"
mc:Ignorable="d">
<TreeView
BorderThickness="0"
ItemsSource="{Binding FileSystem, RelativeSource={RelativeSource AncestorType=UserControl}}"
TreeViewItem.Collapsed="TreeView_Collapsed"
TreeViewItem.Expanded="TreeView_Expanded"
VirtualizingStackPanel.IsVirtualizing="True"
VirtualizingStackPanel.VirtualizationMode="Recycling">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate DataType="{x:Type fe:FileSystemObject}" ItemsSource="{Binding Items}">
<StackPanel Margin="0,2" Orientation="Horizontal">
<Image
Width="14"
Margin="2"
Source="{Binding Image}"
Stretch="Fill" />
<TextBlock
VerticalAlignment="Center"
FontSize="{StaticResource FontSizeSmall}"
Text="{Binding Name}" />
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
主窗口XAML:
<Window
x:Class="MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:fe="clr-namespace:WpfControlLibrary.FileExplorer;assembly=WpfControlLibrary"
xmlns:local="clr-namespace:ModStudio.Client"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:vm="clr-namespace:ModStudio.Client.ViewModels"
Title="MainWindow"
d:DesignHeight="600"
d:DesignWidth="800"
WindowStartupLocation="CenterOwner"
WindowState="Maximized"
mc:Ignorable="d">
<Window.Resources>
<vm:MainWindowViewModel x:Key="MainWindowViewModel" />
</Window.Resources>
<Grid>
<fe:TreeViewUserControl DataContext="{StaticResource MainWindowViewModel}" FileSystem="{Binding ApplicationExplorer}" />
</Grid>
</Window>
主窗口将其DataContext设置为代码隐藏中ViewModel的新实例。MainWindowViewModel有一个名为ApplicationExplorer的属性,它是FileSystemObjectCollection的实例。如前所述,FileSystemObject集合继承自FileSystemObject的ObservableCollection。FileSystemObject实现INotifyPropertyChanged。如果更改ApplicationExplorer属性,控件将保持空白
我有意省略了这里的一些代码,但如果需要,可以添加它们。不要在UserControl中设置DataContext,即删除此行:
Me.DataContext = Me
当您明确地像这样设置DataContext时,您会断开继承链,这意味着绑定到窗口中的ApplicationExplorer属性不再有效:
<fe:TreeViewUserControl DataContext="{StaticResource MainWindowViewModel}"
FileSystem="{Binding ApplicationExplorer}" />
我做了3个改变,让它工作了 已将OnProperty更改为ApplicationExplorer:
Public Property ApplicationExplorer As FileSystemObjectCollection
Get
Return _applicationExplorer
End Get
Set(value As FileSystemObjectCollection)
_applicationExplorer = value
OnPropertyChanged(NameOf(ApplicationExplorer))
End Set
End Property
已更新UserControl中的绑定:
Namespace FileExplorer
Public Class TreeViewUserControl
Inherits UserControl
#Region "Constructors"
Public Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
Me.DataContext = Me
End Sub
#End Region
#Region "Properties"
Public Shared ReadOnly FileSystemProperty As DependencyProperty = DependencyProperty.Register("FileSystem", GetType(FileSystemObjectCollection), GetType(TreeViewUserControl))
Public Property FileSystem As FileSystemObjectCollection
Get
Return CType(GetValue(FileSystemProperty), FileSystemObjectCollection)
End Get
Set(ByVal value As FileSystemObjectCollection)
SetValue(FileSystemProperty, value)
FileExplorer.UpdateLayout()
End Set
End Property
#End Region
Private Function GetFileSystemInfo(ByVal root As String) As FileSystemObjectCollection
Dim items As New FileSystemObjectCollection
' Parse all the directories at the path
For Each dir As String In Directory.GetDirectories(root)
items.Add(New FileSystemObject(dir, root))
Next
' Parse all the file at the path
For Each file As String In Directory.GetFiles(root)
items.Add(New FileSystemObject(file, root))
Next
Return items
End Function
Private Sub TreeView_Collapsed(sender As Object, e As RoutedEventArgs)
Dim node As TreeViewItem = CType(e.OriginalSource, TreeViewItem)
Dim fs As FileSystemObject = CType(node.DataContext, FileSystemObject)
fs.Clear()
End Sub
Private Sub TreeView_Expanded(sender As Object, e As RoutedEventArgs)
Dim node As TreeViewItem = CType(e.OriginalSource, TreeViewItem)
Dim fs As FileSystemObject = CType(node.DataContext, FileSystemObject)
If Not fs.HasChildren Then Exit Sub
fs.Items = GetFileSystemInfo(fs.FullName)
End Sub
End Class
End Namespace
<UserControl
x:Class="FileExplorer.TreeViewUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:fe="clr-namespace:WpfControlLibrary.FileExplorer"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
x:Name="FileExplorer"
d:DesignHeight="300"
d:DesignWidth="400"
mc:Ignorable="d">
<TreeView
BorderThickness="0"
ItemsSource="{Binding FileSystem, RelativeSource={RelativeSource AncestorType=fe:TreeViewUserControl}}"
TreeViewItem.Collapsed="TreeView_Collapsed"
TreeViewItem.Expanded="TreeView_Expanded"
VirtualizingStackPanel.IsVirtualizing="True"
VirtualizingStackPanel.VirtualizationMode="Recycling">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate DataType="{x:Type fe:FileSystemObject}" ItemsSource="{Binding Items}">
<StackPanel Margin="0,2" Orientation="Horizontal">
<Image
Width="14"
Margin="2"
Source="{Binding Image}"
Stretch="Fill" />
<TextBlock
VerticalAlignment="Center"
FontSize="12"
Text="{Binding Name}" />
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
</UserControl>
按照您的建议,从UserControl代码中删除了Me.DataContext=Me
谢谢,我以后会试试的。那你为什么写你的答案而不接受我的呢?