因此，我时常在 Winforms 的遗留应用程序中工作，并不总是熟悉绑定对象的最佳实践。基本上我有一个三部分集，其中有两个人，他们可能只有一种产品，但该产品可能会导致拥有不同的 SKU 集。有没有办法从第一个组合框的值触发组合框的事件和填充？我一直在环顾四周，我要么找到如何绑定组合框的基本数据（我可以做得很好），要么对如何绑定它做一些事情。触发依赖父项更改并更改数据集后不绑定。下面的例子：
POCOS:
Public Class Person
Public Property PersonID As Integer
Public Property FirstName As String
Public Property LastName As String
Public Property ProductId As Integer
Public Property SkuId As Integer
End Class
Public Class Product
Public Property ProductId As Integer
Public Property Description As String
End Class
Public Class Sku
Public Property SKUId As Integer
Public Property ProductId As Integer
Public Property Description As String
End Class
主要代码示例（基本 UI 实际上只有一个标记为“ds”的数据集，它与数据表中的 Person 和 Product POCOS 几乎相同地匹配。datagridview“dgv”，其列绑定到 Person 中的数据，除了名为 SKU 的列没有绑定之外因为我想在事后绑定它，而这正是我失败的地方。
更新于 2016 年 9 月 13 日我可以让下面的代码工作，除了在某些大型解决方案中（我这样做的全部原因）。它基本上不会执行将 cell() 转换为datagridviewcomboboxcell并忽略它并跳过该线。没有为什么，它只是跳过它。我想知道在较大的类中数据网格视图是否会损坏或发生其他情况。
主要代码：
Private _people As List(Of Person) = New List(Of Person)
Private _products As List(Of Product) = New List(Of Product)
Private _SKUs As List(Of Sku) = New List(Of Sku)
Private _initialLoadDone = False
Private _currentRow As Integer? = Nothing
Private Sub DynamicComboBoxDoubleFill_Load(sender As Object, e As EventArgs) Handles MyBase.Load
_products = New List(Of Product)({
New Product With {.ProductId = 1, .Description = "Offline"},
New Product With {.ProductId = 2, .Description = "Online"}
})
Dim s = ""
For Each o In _products
Dim row As DataRow = ds.Tables("tProducts").NewRow
row("ProductId") = o.ProductId
row("Description") = o.Description
ds.Tables("tProducts").Rows.Add(row)
Next
_SKUs = New List(Of Sku)({
New Sku With {.SKUId = 1, .ProductId = 1, .Description = "Mail"},
New Sku With {.SKUId = 2, .ProductId = 1, .Description = "Magazine"},
New Sku With {.SKUId = 3, .ProductId = 2, .Description = "Email"},
New Sku With {.SKUId = 4, .ProductId = 2, .Description = "APIRequest"}
})
Dim items = _SKUs
_people = New List(Of Person)({
New Person With {.PersonID = 1, .FirstName = "Emily", .LastName = "X", .ProductId = 1, .SkuId = 1},
New Person With {.PersonID = 2, .FirstName = "Brett", .LastName = "X", .ProductId = 2, .SkuId = 3}
})
For Each p In _people
Dim row As DataRow = ds.Tables("tPeople").NewRow
row("PersonId") = p.PersonId
row("FirstName") = p.FirstName
row("LastName") = p.LastName
row("ProductId") = p.ProductId
row("SkuId") = p.SkuId
ds.Tables("tPeople").Rows.Add(row)
Next
For Each row As DataGridViewRow In dgv.Rows
ArrangeValuesForSKUComboBox(row)
Next
_initialLoadDone = True
End Sub
Private Sub ArrangeValuesForSKUComboBox(row As DataGridViewRow)
Dim productId = CInt(row.Cells("ProductId")?.Value)
Dim skus = _SKUs.Where(Function(x) x.ProductId = productId).ToList().Select(Function(x) New With {Key .SkuId = x.SKUId, .SkuDesc = x.Description}).ToList()
Dim cell = row.Cells("SKU")
'Yeah I don't always work. In this example I do, in others I won't.
'For this reason I just want more ideas. I don't care if you completely blow up how the binding is done and do something else entirely.
Dim combobox = CType(cell, DataGridViewComboBoxCell)
combobox.DataSource = skus
combobox.ValueMember = "SKUId"
combobox.DisplayMember = "SkuDesc"
combobox.Value = skus.FirstOrDefault()?.SkuId
End Sub
Private Sub dgv_CellValueChanged(sender As Object, e As DataGridViewCellEventArgs) Handles dgv.CellValueChanged
If _initialLoadDone Then
Dim headerText As String = TryCast(sender, DataGridView).Columns(e.ColumnIndex).HeaderText
If headerText = "PRODUCT" Then
ArrangeValuesForSKUComboBox(dgv?.CurrentRow)
End If
End If
End Sub
