使用网格作为ItemsHost

Question

我希望将Grid用作ItemsHost，但是绑定的所有项都没有出现在它们应该出现的（列，行）位置。我该怎么做才能让它正常工作？以下是一个简单的示例：

XAML

<ItemsControl ItemsSource="{Binding DataSet}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <TextBlock Grid.Column="{Binding Col}" Grid.Row="{Binding Row}" Text="{Binding Text}"   />
        </DataTemplate>
    </ItemsControl.ItemTemplate>
    <ItemsControl.Style>
        <Style TargetType="{x:Type ItemsControl}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type ItemsControl}">
                        <Grid HorizontalAlignment="Stretch" IsItemsHost="True">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition />
                                <ColumnDefinition />
                            </Grid.ColumnDefinitions>
                            <Grid.RowDefinitions>
                                <RowDefinition />
                                <RowDefinition />
                            </Grid.RowDefinitions>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </ItemsControl.Style>
</ItemsControl>

Codebehind（代码后置）

Class Window1 

    Private myTestData As TestData

    Public Sub New()
        ' This call is required by the Windows Form Designer.
        InitializeComponent()

        ' Add any initialization after the InitializeComponent() call.
        myTestData = New TestData()
        Me.DataContext = myTestData
    End Sub

End Class

Class TestData

    Private myDataSet As List(Of DataPoint)
    Public Property DataSet() As List(Of DataPoint)
        Get
            Return myDataSet
        End Get
        Set(ByVal value As List(Of DataPoint))
            myDataSet = value
        End Set
    End Property

    Public Sub New()
        Me.DataSet = New List(Of DataPoint)
        For x As Integer = 0 To 1
            For y As Integer = 0 To 1
                Me.DataSet.Add(New DataPoint(x, y, "Column " + x.ToString + ", Row " + y.ToString))
            Next
        Next
    End Sub

End Class

Class DataPoint

    Private myRow As Integer
    Public Property Row() As Integer
        Get
            Return myRow
        End Get
        Set(ByVal value As Integer)
            myRow = value
        End Set
    End Property

    Private myCol As Integer
    Public Property Col() As Integer
        Get
            Return myCol
        End Get
        Set(ByVal value As Integer)
            myCol = value
        End Set
    End Property

    Private myText As String
    Public Property Text() As String
        Get
            Return myText
        End Get
        Set(ByVal value As String)
            myText = value
        End Set
    End Property

    Public Sub New(ByVal x As Integer, ByVal y As Integer, ByVal name As String)
        Me.Row = y
        Me.Col = x
        Me.Text = name
    End Sub

End Class

- Bryan Anderson

Answer 1

由于你正在使用一个ItemsControl控件，每个项都会生成一个容器。这个容器(对于普通的ItemsControl而言是ContentPresenter的实例)包装了TextBlock，并且是Grid的直接子元素。因此，Grid甚至不会看到TextBlock上的Column和Row属性，因为它实际上是查找容器。

你可以通过设置ItemContainerStyle来绑定容器的适当属性来解决这个问题:

<ItemsControl.ItemContainerStyle>
    <Style TargetType="ContentPresenter">
        <Setter Property="Grid.Column" Value="{Binding Column}"/>
        <Setter Property="Grid.Row" Value="{Binding Row}"/>
    </Style>
</ItemsControl.ItemContainerStyle>

- Kent Boogaart

Answer 2

可能的解决方法：如果您使用UniformGrid，则可能不需要指定行和列。

- Earwicker