Mvvm 复选框命令，选中-确定，取消选中不确定，如何绑定取消选中命令？

我在将取消选中命令附加到复选框时遇到问题。或者更正确，我不知道如何编码它。下面是我的check命令代码，如果取消选中也能正常工作，它应该是什么样子

视图：

命令：

Public Class ToggleCheckedCommandBehaviour
    Inherits CommandBehaviorBase(Of CheckBox)

    Public Sub New(ByVal checkableObject As CheckBox)
        MyBase.New(checkableObject)
        AddHandler checkableObject.Checked, AddressOf checkableObject_Checked
    End Sub

    Private Sub checkableObject_Checked(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs)
        CommandParameter = TargetObject.Name
        ExecuteCommand()
    End Sub
End Class

Public NotInheritable Class Checked

    Private Sub New()
    End Sub

    Private Shared ReadOnly SelectedCommandBehaviorProperty As DependencyProperty = _
    DependencyProperty.RegisterAttached("SelectedCommandBehavior", _
                                        GetType(ToggleCheckedCommandBehaviour), _
                                        GetType(Checked), _
                                        Nothing)

    Private Shared ReadOnly CommandProperty As DependencyProperty = _
    DependencyProperty.RegisterAttached("Command", _
                                        GetType(ICommand), _
                                        GetType(Checked), _
                                        New PropertyMetadata(AddressOf OnSetCommandCallback))


    Public Shared Sub SetCommand(ByVal CheckBox As CheckBox, ByVal command As ICommand)
        CheckBox.SetValue(CommandProperty, command)
    End Sub

    Public Shared Function GetCommand(ByVal CheckBox As CheckBox) As ICommand
        Return TryCast(CheckBox.GetValue(CommandProperty), ICommand)
    End Function

    Private Shared Sub OnSetCommandCallback(ByVal dependencyObject As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
        Dim CheckBox = TryCast(dependencyObject, CheckBox)
        If Not CheckBox Is Nothing Then
            Dim behavior = GetOrCreateBehavior(CheckBox)
            behavior.Command = TryCast(e.NewValue, ICommand)
        End If
    End Sub

    Private Shared Function GetOrCreateBehavior(ByVal CheckBox As CheckBox) As ToggleCheckedCommandBehaviour
        Dim behavior = TryCast(CheckBox.GetValue(SelectedCommandBehaviorProperty), ToggleCheckedCommandBehaviour)
        If behavior Is Nothing Then
            behavior = New ToggleCheckedCommandBehaviour(CheckBox)
            CheckBox.SetValue(SelectedCommandBehaviorProperty, behavior)
        End If
        Return behavior
    End Function

End Class
End Namespace

如前所述，check命令工作正常，并且连接到它的命令和方法得到fires，我需要做什么才能使uncheck也工作？

---

关于信息，我正在使用PRISM、CAL、MVVM和SL4-在VB.NET中，Checked命令工作正常这一事实意味着附加的行为得到了正确实现。也就是说，该行为只监视您在此行中指定的单个事件：

AddHandler checkableObject.Checked, AddressOf checkableObject_Checked

因此，您正在订阅Checkbox控件的事件。由于要控制复选框未选中，只需使用事件创建另一个附加行为。这假设您希望在选中/取消选中按钮时执行不同的命令。如果使用相同的命令，那么绑定到属性就足够了

我希望这有帮助

Public Class ToggleCheckedCommandBehaviour
    Inherits CommandBehaviorBase(Of CheckBox)

    Public Sub New(ByVal checkableObject As CheckBox)
        MyBase.New(checkableObject)
        AddHandler checkableObject.Checked, AddressOf checkableObject_Checked
    End Sub

    Private Sub checkableObject_Checked(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs)
        CommandParameter = TargetObject.Name
        ExecuteCommand()
    End Sub
End Class

Public NotInheritable Class Checked

    Private Sub New()
    End Sub

    Private Shared ReadOnly SelectedCommandBehaviorProperty As DependencyProperty = _
    DependencyProperty.RegisterAttached("SelectedCommandBehavior", _
                                        GetType(ToggleCheckedCommandBehaviour), _
                                        GetType(Checked), _
                                        Nothing)

    Private Shared ReadOnly CommandProperty As DependencyProperty = _
    DependencyProperty.RegisterAttached("Command", _
                                        GetType(ICommand), _
                                        GetType(Checked), _
                                        New PropertyMetadata(AddressOf OnSetCommandCallback))


    Public Shared Sub SetCommand(ByVal CheckBox As CheckBox, ByVal command As ICommand)
        CheckBox.SetValue(CommandProperty, command)
    End Sub

    Public Shared Function GetCommand(ByVal CheckBox As CheckBox) As ICommand
        Return TryCast(CheckBox.GetValue(CommandProperty), ICommand)
    End Function

    Private Shared Sub OnSetCommandCallback(ByVal dependencyObject As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
        Dim CheckBox = TryCast(dependencyObject, CheckBox)
        If Not CheckBox Is Nothing Then
            Dim behavior = GetOrCreateBehavior(CheckBox)
            behavior.Command = TryCast(e.NewValue, ICommand)
        End If
    End Sub

    Private Shared Function GetOrCreateBehavior(ByVal CheckBox As CheckBox) As ToggleCheckedCommandBehaviour
        Dim behavior = TryCast(CheckBox.GetValue(SelectedCommandBehaviorProperty), ToggleCheckedCommandBehaviour)
        If behavior Is Nothing Then
            behavior = New ToggleCheckedCommandBehaviour(CheckBox)
            CheckBox.SetValue(SelectedCommandBehaviorProperty, behavior)
        End If
        Return behavior
    End Function

End Class
End Namespace

AddHandler checkableObject.Checked, AddressOf checkableObject_Checked