如何将DataTemplate控件绑定到ObservableCollections的item属性

Question

我正在尝试创建一个自定义列表框来显示一些数据，但是我找不到在DataTemplate控件和items属性之间设置绑定的正确方法。

我有以下POCO课程：

Namespace Model
    Public Class Version

        Property Numero As String

        Property Checksum As String

    End Class
End Namespace

而这个ViewModel类：

Imports System.ComponentModel
Imports System.Collections.ObjectModel

Namespace ViewModel
    Public Class VersionViewModel
        Implements INotifyPropertyChanged


        Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged


        Private _ListaVersiones As ObservableCollection(Of Model.Version)
        Public Property ListaVersiones As ObservableCollection(Of Model.Version)
            Get
                Return _ListaVersiones
            End Get
            Set(value As ObservableCollection(Of Model.Version))
                _ListaVersiones = value
                NotifyPropertyChanged("Versiones")
            End Set
        End Property

        Private Sub NotifyPropertyChanged(ByVal propertyName As String)
            RaiseEvent PropertyChanged(Me, New ComponentModel.PropertyChangedEventArgs(propertyName))
        End Sub


    End Class
End Namespace

我正在尝试在以下XAML中使用此ViewModel：

<Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:vm="clr-namespace:Projeto.ViewModel"
    Title="MainWindow" Height="350" Width="525" Loaded="Window_Loaded">
    <Window.Resources>
        <vm:VersionViewModel x:Key="ViewModel"/>
        <Style 
            BasedOn="{StaticResource {x:Type ListBox}}"
            TargetType="ListBox"
            x:Key="EstiloGridVersion">

            <Setter Property="ItemTemplate">
                <Setter.Value>
                    <DataTemplate>
                        <Grid Background="Blue">
                            <Border Background="Red" x:Name="border" BorderBrush="Gray" CornerRadius="6" Height="30" BorderThickness="1">

                                <!-- The error is in the Binding Path -->
                                <TextBlock Text="{Binding  Path=ListaVersiones.Numero}"/>
                            </Border>
                        </Grid>

                    </DataTemplate>
                </Setter.Value>
            </Setter>

        </Style>
    </Window.Resources>

    <ListBox x:Name="GridVersion" Style="{StaticResource EstiloGridVersion}" ItemsSource="{Binding Source={StaticResource ViewModel}, Path=ListaVersiones}">

    </ListBox>
</Window>

TextBlock绑定选项给我一个错误“无法解析符号X”。

什么是正确的方法？

更新

这是“窗口加载”事件代码：

Class MainWindow

    Private Sub Window_Loaded(sender As Object, e As RoutedEventArgs)
        Dim versiones As New VersionViewModel
        versiones.ListaVersiones = New ObjectModel.ObservableCollection(Of Model.Version)()
        versiones.ListaVersiones.Add(New Model.Version() With {.Numero = "07.0201", .Checksum = "0450a4s6540a6s5006a5s4"})
        versiones.ListaVersiones.Add(New Model.Version() With {.Numero = "07.0207", .Checksum = "243jkh234jh23j3406a5s4"})

        GridVersion.ItemsSource = versiones
    End Sub

End Class

Answer 1

由于ItemsSource设置为ObservableCollection<Model.Version>每个项目都是Model.Version类型，并且每个ListBoxItem都是DataContext ，因此在您的DataTemplate您需要引用Model.Version的属性。

<TextBlock Text="{Binding Path=Numero}"/>

另外，它不应该编译，但是问题是当您分配ItemsSource

GridVersion.ItemsSource = versiones

您应该分配versiones.ListaVersiones代替

GridVersion.ItemsSource = versiones.ListaVersiones

另一件事是，当您为ListaVersiones属性提高NotifyPropertyChanged ，您需要传递ListaVersiones （确切的属性名称）而不是像现在一样传递Versiones

NotifyPropertyChanged("ListaVersiones")

并且由于您是手动设置ItemsSource ，因此无需在XAML中进行设置

ItemsSource="{Binding Source={StaticResource ViewModel}, Path=ListaVersiones}"

您在Window_Loaded创建的新VersionViewModel实例与您在XAML中创建的实例不同

<vm:VersionViewModel x:Key="ViewModel"/>