BindingSource和父DataRelation

Question

我有4个DataTables：

• 产品: pk_product，name，fk_color，fk_size。
• 颜色: pk_color，名字。
• 大小: pk_size，姓名。
• 日志: pk_log，fk_product，date。

产品表绑定到“主”BindingSource。将日志表(子关系)绑定到主绑定就像一种魅力。但是绑定颜色和大小表(父关系)失败。

我做错什么了？

    Dim data As New DataSet()

    With data.Tables.Add("COLOR")
        .Columns.AddRange(New DataColumn() {New DataColumn("PK_COLOR", GetType(Int32)), New DataColumn("NAME", GetType(String))})
        .PrimaryKey = New DataColumn() {.Columns(0)}
        .BeginLoadData()
        For pk_color As Integer = 1 To 5
            .Rows.Add(pk_color, String.Format("Color #{0}", pk_color))
        Next
        .EndLoadData()
        .AcceptChanges()
    End With

    With data.Tables.Add("SIZE")
        .Columns.AddRange(New DataColumn() {New DataColumn("PK_SIZE", GetType(Int32)), New DataColumn("NAME", GetType(String))})
        .PrimaryKey = New DataColumn() {.Columns(0)}
        .BeginLoadData()
        For pk_size As Integer = 6 To 10
            .Rows.Add(pk_size, String.Format("Size #{0}", pk_size))
        Next
        .EndLoadData()
        .AcceptChanges()
    End With

    With data.Tables.Add("PRODUCT")
        .Columns.AddRange(New DataColumn() {New DataColumn("PK_PRODUCT", GetType(Int32)), New DataColumn("NAME", GetType(String)), New DataColumn("FK_COLOR", GetType(Int32)), New DataColumn("FK_SIZE", GetType(Int32))})
        .PrimaryKey = New DataColumn() {.Columns(0)}
        .BeginLoadData()
        Dim pk_product As Integer = 1
        For fk_color As Integer = 1 To 5
            For fk_size As Integer = 6 To 10
                .Rows.Add(pk_product, String.Format("Product #{0}", pk_product), fk_color, fk_size)
                pk_product += 1
            Next
        Next
        .EndLoadData()
        .AcceptChanges()
    End With

    With data.Tables.Add("LOG")
        .Columns.AddRange(New DataColumn() {New DataColumn("PK_LOG", GetType(Int32)), New DataColumn("FK_PRODUCT", GetType(Int32)), New DataColumn("DATE", GetType(DateTime))})
        .PrimaryKey = New DataColumn() {.Columns(0)}
        .BeginLoadData()
        For pk_log As Integer = 1 To 15
            .Rows.Add(pk_log, pk_log, DateTime.Now().AddDays(CDbl(pk_log * -1)))
        Next
        .EndLoadData()
        .AcceptChanges()
    End With

    Dim productColorRelation As DataRelation = data.Relations.Add("PRODUCT_FK_COLOR", data.Tables("COLOR").Columns("PK_COLOR"), data.Tables("PRODUCT").Columns("FK_COLOR"))
    Dim productSizeRelation As DataRelation = data.Relations.Add("PRODUCT_FK_SIZE", data.Tables("SIZE").Columns("PK_SIZE"), data.Tables("PRODUCT").Columns("FK_SIZE"))
    Dim logProductRelation As DataRelation = data.Relations.Add("LOG_FK_PRODUCT", data.Tables("PRODUCT").Columns("PK_PRODUCT"), data.Tables("LOG").Columns("FK_PRODUCT"))

    data.AcceptChanges()

    'Master binding:
    Dim productBinding As BindingSource = New BindingSource(data, "PRODUCT")

    'Parent bindings: (Do NOT work)
    Dim productColorBinding As BindingSource = New BindingSource(productBinding, productColorRelation.RelationName)
    Dim productSizeBinding As BindingSource = New BindingSource(productBinding, productSizeRelation.RelationName)

    'Child binding:
    Dim logProductBinding As BindingSource = New BindingSource(productBinding, logProductRelation.RelationName)

Answer 1

如果只需要与颜色和大小的关系来显示相关数据，则可以尝试反转这些关系并禁用check约束。定义这样的关系：

Dim productColorRelation As DataRelation = data.Relations.Add("PRODUCT_FK_COLOR",  data.Tables("PRODUCT").Columns("FK_COLOR"),data.Tables("COLOR").Columns("PK_COLOR"),false)
Dim productSizeRelation As DataRelation = data.Relations.Add("PRODUCT_FK_SIZE", data.Tables("PRODUCT").Columns("FK_SIZE"), data.Tables("SIZE").Columns("PK_SIZE"), false)

'Parent bindings: (This should work with the reverse relations)
Dim productColorBinding As BindingSource = New BindingSource(productBinding, productColorRelation.RelationName)
Dim productSizeBinding As BindingSource = New BindingSource(productBinding, productSizeRelation.RelationName)

祝好运!