我正在尝试实现一个DataGrid，其中一个列具有复杂对象，而comboBox（在网格外）具有此列的同一时间对象的列表。使用WPF和MVVM。
当我在数据网格中选择Line时，我希望组合框显示相应的值。
但我不知道我做错了什么。 有人可以帮忙吗？
<ComboBox x:Name="cmbResourceList"
HorizontalAlignment="Left"
ItemsSource="{Binding MainListSource}"
DisplayMemberPath="Description"
SelectedValue="{Binding Path=ScheduleVM.Schedule.ResourceList}"
Width="185"/>
<DataGrid x:Name="dgScheduleItems"
AutoGenerateColumns="False"
ItemsSource="{Binding Path=ScheduleSource}"
SelectionMode="Single"
IsReadOnly="True"
SelectedItem="SelectedSchedule">
<DataGrid.Columns>
<DataGridTextColumn Header="Id" Binding="{Binding Id}" Width="40"/>
<DataGridTextColumn Header="Resource List" Binding="{Binding ResourceList.Description}" Width="*"/>
<DataGridTextColumn Header="Task List" Binding="{Binding TaskList.Description}" Width="*"/>
<DataGridTextColumn Header="Description" Binding="{Binding Description}" Width="100"/>
</DataGrid.Columns>
</DataGrid>
这里是Vb.Net中的课程
Public Class MainList
Public Property Id As Integer
Public Property Description As String
End Class
Public Class Schedule
Public Property Id As Integer
Public Property Description As String
Public Property ResourceList As MainList
Public Property TaskList As MainList
End Class
Public Class MainListRepository
Private _mainLists As List(Of MainList)
Public Sub New()
_mainLists = New List(Of MainList) From
{
New MainList() With {.Id = 1, .Description = "First List"},
New MainList() With {.Id = 2, .Description = "Second List"},
New MainList() With {.Id = 3, .Description = "Third List"}
}
End Sub
Public Function GetMainLists() As List(Of MainList)
Return _mainLists
End Function
End Class
Public Class ScheduleRepository
Private _schedules As List(Of Schedule)
Public Sub New()
_schedules = New List(Of Schedule) From
{
New Schedule() With {.Id = 1, .Description = "Schedule 1", .ResourceList = New MainList() With {.Id = 2, .Description = "Second List"}, .TaskList = New MainList() With {.Id = 1, .Description = "First List"}},
New Schedule() With {.Id = 2, .Description = "Schedule 2", .ResourceList = New MainList() With {.Id = 1, .Description = "First List"}, .TaskList = New MainList() With {.Id = 2, .Description = "Second List"}},
New Schedule() With {.Id = 3, .Description = "Schedule 3", .ResourceList = New MainList() With {.Id = 1, .Description = "First List"}, .TaskList = New MainList() With {.Id = 3, .Description = "Third List"}},
New Schedule() With {.Id = 4, .Description = "Schedule 4", .ResourceList = New MainList() With {.Id = 3, .Description = "Third List"}, .TaskList = New MainList() With {.Id = 1, .Description = "First List"}}
}
End Sub
Public Function GetSchedules() As List(Of Schedule)
Return _schedules
End Function
End Class
Public MustInherit Class ViewModelBase
Implements INotifyPropertyChanged
Protected Sub New()
End Sub
Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged
Protected Overridable Sub OnPropertyChanged(ByVal propertyName As String)
Me.VerifyPropertyName(propertyName)
Dim handler As PropertyChangedEventHandler = Me.PropertyChangedEvent
If handler IsNot Nothing Then
Dim e = New PropertyChangedEventArgs(propertyName)
handler(Me, e)
End If
End Sub
Private privateThrowOnInvalidPropertyName As Boolean
Protected Overridable Property ThrowOnInvalidPropertyName() As Boolean
Get
Return privateThrowOnInvalidPropertyName
End Get
Set(ByVal value As Boolean)
privateThrowOnInvalidPropertyName = value
End Set
End Property
End Class
Public Class ScheduleVM
Inherits ViewModelBase
Private _Schedule As Schedule
Public Property Schedule() As Schedule
Get
Return _Schedule
End Get
Set(ByVal value As Schedule)
_Schedule = value
OnPropertyChanged("Schedule")
End Set
End Property
Public Sub New(schedule As Schedule)
_Schedule = schedule
End Sub
End Class
Friend Class SchedulePopupVM
Inherits ViewModelBase
Private _ScheduleSource As List(Of Schedule)
Public Property ScheduleSource() As List(Of Schedule)
Get
Return _ScheduleSource
End Get
Set(ByVal value As List(Of Schedule))
_ScheduleSource = value
OnPropertyChanged("ScheduleSource")
End Set
End Property
Private _MainListSource As List(Of MainList)
Public Property MainListSource() As List(Of MainList)
Get
Return _MainListSource
End Get
Set(ByVal value As List(Of MainList))
_MainListSource = value
OnPropertyChanged("MainListSource")
End Set
End Property
Private _SelectedSchedule As Schedule
Public Property SelectedSchedule() As Schedule
Get
Return _SelectedSchedule
End Get
Set(ByVal value As Schedule)
_SelectedSchedule = value
Me.ScheduleVM = New ScheduleVM(value)
OnPropertyChanged("SelectedSchedule")
End Set
End Property
Private _ScheduleVM As ScheduleVM
Public Property ScheduleVM() As ScheduleVM
Get
Return _ScheduleVM
End Get
Set(ByVal value As ScheduleVM)
_ScheduleVM = value
OnPropertyChanged("ScheduleVM")
End Set
End Property
Public Sub New()
Dim repo As ScheduleRepository = New ScheduleRepository()
Dim repoMain As MainListRepository = New MainListRepository()
_ScheduleSource = repo.GetSchedules()
_MainListSource = repoMain.GetMainLists()
End Sub
End Class
答案 0 :(得分：1)
一些事情。
您的SelectedValues（在您的ComboBox上）都绑定到项目集合。您不希望这样，这些属性旨在绑定到项集合中的各个项目。
接下来，您对SelectedItem的{{1}}的绑定是错误的。将其更新为（注意绑定关键字和大括号）：
DataGrid接下来，对于您的 <DataGrid x:Name="dgScheduleItems"
AutoGenerateColumns="False"
ItemsSource="{Binding Path=ScheduleSource}"
SelectionMode="Single"
IsReadOnly="True"
SelectedItem="{Binding SelectedSchedule}"
Margin="0,106,0,0">
，您希望绑定到单个值。但是，您绑定到ComboBoxes的值必须是对其ItemsSource中某个值的引用。
更新它们以绑定到新属性。例如：
SelectedValue然后，在SelectedSchedule属性更改时设置NEW属性（MainListSourceSelectedValue）。像（在c＃中）
的东西 <ComboBox x:Name="cmbTaskList"
HorizontalAlignment="Left"
ItemsSource="{Binding MainListSource}"
DisplayMemberPath="Description"
SelectedValue="{Binding MainListSourceSelectedValue, Mode=TwoWay}"
Margin="244,30,0,0"
VerticalAlignment="Top"
Width="185"/>