我ElementHost
在 Winforms 应用程序中有一个 WPF。用户控件有一些文本和一个TreeView
应该显示应用程序提供的可用命令的树。
我是 WPF 新手(这是一个学习练习),所以在绑定数据时遇到了一些问题。
我创建了一个CommandTreeViewModel
类来充当我的视图模型。它有一个FirstGeneration
属性是IEnumerable(of CommandViewModel)
. 该类CommandViewModel
又具有一些简单的属性来描述Command
包括Children
属性(同样是IEnumerable(of CommandViewModel)
)。
我已经Public Property ViewModel As CommandTreeViewModel
向我的 WPF 用户控件添加了一个,该控件现在由我的 winforms 应用程序设置。
我不知道该怎么做是将我在 ViewModel 属性中提交的数据绑定到 TreeView。(有什么方法可以强输入我的 XAML 绑定的 ViewModel 类 a-la MVC?)
我已经包含了我认为下面的相关代码,以备不时之需。
用户控制
Public Class WPFCommandTree
Implements INotifyPropertyChanged
Public Property ViewModel As CommandTreeViewModel
Get
Return DirectCast(GetValue(ViewModelProperty), CommandTreeViewModel)
End Get
Set(ByVal value As CommandTreeViewModel)
If Not value.Equals(DirectCast(GetValue(ViewModelProperty), CommandTreeViewModel)) Then
SetValue(ViewModelProperty, value)
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("ViewModelProperty"))
End If
End Set
End Property
Public Shared ReadOnly ViewModelProperty As DependencyProperty = _
DependencyProperty.Register("ViewModel",
GetType(CommandTreeViewModel), GetType(Window),
New FrameworkPropertyMetadata(Nothing))
Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
End Class
XAML
<UserControl x:Class="WPFCommandTree"
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"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="60" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<TextBlock FontSize="30" HorizontalAlignment="Center" VerticalAlignment="Center">Test</TextBlock>
<TreeView ItemsSource="{Binding FirstGeneration}"
VerticalAlignment="Stretch"
HorizontalAlignment="Stretch"
Grid.Row="1"
DataContext="{Binding}">
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="IsExpanded"
Value="{Binding IsExpanded, Mode=TwoWay}" />
<Setter Property="IsSelected"
Value="{Binding IsSelected, Mode=TwoWay}" />
<Setter Property="FontWeight"
Value="Normal" />
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="FontWeight" Value="Bold" />
</Trigger>
</Style.Triggers>
</Style>
</TreeView.ItemContainerStyle>
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Children}">
<TextBlock Text="{Binding Name}" />
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
</Grid>
</UserControl>
查看模型
Public Class CommandTreeViewModel
Public Property RootCommand As CommandViewModel
Public Property FirstGeneration As ReadOnlyCollection(Of CommandViewModel)
Public Sub New(ByVal RootCommand As Command)
_RootCommand = New CommandViewModel(RootCommand)
_FirstGeneration = New ReadOnlyCollection(Of CommandViewModel)(New CommandViewModel() {_RootCommand})
End Sub
Public Sub New(ByVal RootCommand As CommandViewModel)
Me.RootCommand = RootCommand
Me.FirstGeneration = New ReadOnlyCollection(Of CommandViewModel)(New CommandViewModel() {_RootCommand})
End Sub
Public Sub New(ByVal RootCommands As IEnumerable(Of CommandViewModel))
Me.RootCommand = RootCommands.First
Me.FirstGeneration = New ReadOnlyCollection(Of CommandViewModel)(RootCommands.ToList)
End Sub
End Class
Public Class CommandViewModel
Implements INotifyPropertyChanged
Public Property Command As Command
Public Property Children As ReadOnlyCollection(Of CommandViewModel)
Public Property Parent As CommandViewModel
Public Property Name As String
Private Property _IsSelected As Boolean
Public Property IsSelected() As Boolean
Get
Return _isSelected
End Get
Set(ByVal value As Boolean)
If value <> _isSelected Then
_isSelected = value
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("IsSelected"))
End If
End Set
End Property
Private Property _IsExpanded As Boolean
Public Property IsExpanded() As Boolean
Get
Return _IsExpanded
End Get
Set(ByVal value As Boolean)
If value <> IsExpanded Then
_IsExpanded = value
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("IsExpanded"))
If _IsExpanded And _Parent IsNot Nothing Then
_Parent.IsExpanded = True
End If
End If
End Set
End Property
Public Sub New(ByVal Command As Command)
Me.New(Command, Nothing)
End Sub
Private Sub New(ByVal Command As Command, ByVal Parent As CommandViewModel)
_Command = Command
_Parent = Parent
If Command.Children IsNot Nothing AndAlso Command.Children.Count > 0 Then
_Children = New ReadOnlyCollection(Of CommandViewModel)(
Command.Children.Select(Function(x) New CommandViewModel(x, Me)
).ToList)
End If
End Sub
Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
End Class
如您所见,我并不清楚我需要做什么,并且一直在尝试从各种教程中破解一些代码。大多数只是 WPF。
运行上面的代码正确加载了控制(我可以在我的表单上看到“测试”文本),但TreeView
仍然是空白的。没有错误被抛出。我假设这是因为我没有正确绑定数据。
最后,我还不清楚我的哪些房产需要成为 DP?用户控件、视图模型、模型子项?我只是不清楚绑定是如何工作的。