Question

假设我有一个数据网格，其绑定对象的类型为ObjectVM：

  Public Class ObjectVM
    Implements INotifyPropertyChanged
    Public Event PropertyChanged(sender As Object, e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged

    Public Property NestedObject As New NestedVM

End Class

NestedVM定义为：

 Public Class NestedVM
    Implements INotifyPropertyChanged
    Public Event PropertyChanged(sender As Object, e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged

    Private _SubValue As Double
    Private _Value As Double

    Public Property Value As Double
        Get
            Return _Value
        End Get
        Set(value As Double)
            _Value = value
            RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("Value"))
        End Set
    End Property

    Public Property SubValue As Double
        Get
            Return _SubValue
        End Get
        Set(value As Double)
            _SubValue = value
            RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("SubValue"))
        End Set
    End Property
End Class

我已经定义了一个datagridtextcolumn，其中cellstyle的模板已被覆盖以包含第二个TextBlock。我希望列的主要文本绑定到（嵌套）属性Value，并希望第二个TextBlock绑定到（嵌套）属性SubValue。为实现此目的，已将附加属性NumberSource（Double类型）添加到GridColumnProperties中。在自定义controltemplate中，第二个Textblock绑定到此NumberSource，NumberSource又绑定到SubValue：

  <DataGridTextColumn Binding="{Binding NestedObject.Value}" local:GridColumnProperties.NumberSource="{Binding NestedObject.SubValue}" >
                <DataGridTextColumn.CellStyle>
                    <Style TargetType="DataGridCell">
                        <Setter Property="Template" Value="{StaticResource NumberTemplate}"/>
                    </Style>
                </DataGridTextColumn.CellStyle>

但是，如果将NumberSource设置为文字值，这似乎只能起作用;当NumberSource像上面绑定一样时，它会失败。这是当前附加的属性定义：

Public NotInheritable Class GridColumnProperties
Private Sub New()
End Sub
Public Shared ReadOnly NumberSourceProperty As DependencyProperty = DependencyProperty.RegisterAttached("NumberSource", GetType(Double), GetType(GridColumnProperties), New PropertyMetadata())

Public Shared Sub SetNumberSource(obj As DependencyObject, value As Double)
    obj.SetValue(NumberSourceProperty, value)
End Sub

Public Shared Function GetNumberSource(obj As DependencyObject) As Double
    Return CType(obj.GetValue(NumberSourceProperty), Double)
End Function

结束班

如何让依赖项属性正确绑定到SubValue？

Cell ControlTemplate绑定到附加属性绑定到视图模型的属性

0 个答案: