势必孩子EntitySet的儿童的BindingSource不更新(Child bindingsou

我有一个表，的sampleData，有一个子表，测量。在我的WinForm，frmMain，单一的sampleData对象绑定到SampleDataBindingSource; 该MeasurementsBindingSource有SampleDataBindingSource作为它的数据源和测量它的数据成员。一组文本框被绑定到SampleDataBindingSource的; 一个DataGridView势必MeasurementsBindingSource。

对于frmMain，我也有一个主持人类，倍美力，其中包含类型的sampleData的属性，CurrentSample。该SampleDataBindingSource.DataSource势必倍美力的CurrentSample财产。

当测量的性能足以已被分配，它计算FiringFactor和，如果FiringFactor不为1，它增加了一个测量项目的CurrentSample的测量EntitySet的：

Partial Class Measurement

    Private Sub UpdateFiringFactor()
        Dim necessaryDataIsAvailable As Boolean = (Me.CrucibleMass IsNot Nothing And _
                                                   Me.CrucibleSampleFiredMass IsNot Nothing And _
                                                   Me.CrucibleSampleMass IsNot Nothing)
        If necessaryDataIsAvailable Then
            Me.FiringFactor = CDbl((Me.CrucibleSampleFiredMass - Me.CrucibleMass) / (Me.CrucibleSampleMass - Me.CrucibleMass))
            If Me.FiringFactor <> 1 Then
                Me.SampleData.AddNewMeasurement()
            End If
        End If
    End Sub

    Private Sub OnCrucibleMassChanged()
        UpdateFiringFactor()
    End Sub


    Private Sub OnCrucibleSampleFiredMassChanged()
        UpdateFiringFactor()
    End Sub


    Private Sub OnCrucibleSampleMassChanged()
        UpdateFiringFactor()
    End Sub
End Class

当我在datagridview的输入值CrucibleMass，CrucibleSampleMass和CrucibleSampleFiredMass的UpdateFiringFactor方法不正确地运行，我终于得到另一个测量项目添加到CurrentSample的测量EntitySet的。然而，在DataGridView不显示新行和MeasurementsBindingSource只有1条记录（但CurrentSample.Measurements.Count = 2 ）。

为什么在改变CurrentSample.Measurements不会传播到MeasurementsBindingSource ？我曾尝试MeasurementsBindingSource.ResetBindings(False) ， MeasurementsDataGridView.Refresh ， SampleDataBindingSource.ResetBindings(False) ，但似乎没有任何更新MeasurementsBindingSource或其datagridview的。

这是我发现的EntitySet的/ BindingSource的问题的解决方案：

Imports System.ComponentModel

Partial Class Measurement

    Public Sub ChangeCrucibleMass(ByVal thisMass As Double)
        CrucibleMass = thisMass
        UpdateFiringFactor()
    End Sub

    Public Sub ChangeCrucibleSampleMass(ByVal thisMass As Double)
        CrucibleSampleMass = thisMass
        UpdateFiringFactor()
    End Sub

    Public Sub ChangeCrucibleSampleFiredMass(ByVal thisMass As Double)
        CrucibleSampleFiredMass = thisMass
        UpdateFiringFactor()
    End Sub

    Private Sub UpdateFiringFactor()
        If AllDataAreAvailable() Then
            FiringFactor = (CrucibleSampleFiredMass - CrucibleMass) / (CrucibleSampleMass - CrucibleMass)
            Me.Sample.OnMeasurementsChanged(Nothing, Nothing)
        End If
    End Sub

    Private Function AllDataAreAvailable() As Boolean
        AllDataAreAvailable = False
        Dim allFieldsHaveValue As Boolean = (CrucibleMass IsNot Nothing And CrucibleSampleFiredMass IsNot Nothing And CrucibleSampleMass IsNot Nothing)
        If allFieldsHaveValue Then
            Dim denominatorIsNotZero As Boolean = (CrucibleSampleMass - CrucibleMass) <> 0
            Return denominatorIsNotZero
        End If

    End Function

End Class

Partial Class Sample

    Public Sub OnMeasurementsChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Handles Me.PropertyChanged
        If Me.Measurements.Count > 0 AndAlso Me.Measurements.Last.FiringFactor IsNot Nothing AndAlso Me.Measurements.Last.FiringFactor <> 1 Then
            Me.Measurements.Add(New Measurement With {.CrucibleMass = Me.Measurements.Last.CrucibleMass})
            RaiseEvent RefreshMeasurementsBinding()
        End If
    End Sub

    Private Sub OnCreated()
        Me.Measurements.Add(New Measurement)
    End Sub

    Public Event RefreshMeasurementsBinding()

End Class

下面是形式的截图：

和代码隐藏：

Imports System.ComponentModel

Public Class Form1

    Private WithEvents newSample As Sample

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        newSample = SampleConduit.GetSample(1)
        'newSample = New Sample
        Me.SampleBindingSource.DataSource = newSample
        OnRefreshMeasurementsBinding()

    End Sub

    Private Sub OnRefreshMeasurementsBinding() Handles newSample.RefreshMeasurementsBinding
        Me.MeasurementsBindingSource.DataSource = newSample.Measurements.GetNewBindingList
    End Sub


    Private Sub MeasurmentsDataGridView_CellClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles MeasurmentsDataGridView.CellClick
        Me.MeasurementsBindingSource.EndEdit()
        Dim currentMeasurement = CType(Me.MeasurementsBindingSource.Current, Measurement)
        Select Case e.ColumnIndex
            Case 0
                currentMeasurement.ChangeCrucibleMass(GetMeasurement)
            Case 1
                currentMeasurement.ChangeCrucibleSampleMass(GetMeasurement)
            Case 2
                currentMeasurement.ChangeCrucibleSampleFiredMass(GetMeasurement)
        End Select
    End Sub

    Private Function GetMeasurement() As Double
        Return CDbl(InputBox("Measurement:", "Get Measurement", "0"))
    End Function

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
        Dim currentSample = CType(Me.SampleBindingSource.Current, Sample)
        SampleConduit.SaveSample(currentSample)
    End Sub
End Class

该解决方案取决于在样本类的RefreshMeasurementsBinding事件和在表格中OnRefreshMeasurementsBinding方法。通常设置MeasurementsBindingSource对EntitySet的似乎有点缺憾的测量方法GetNewBindingList，但它的作品。

见项目＃3关于此论坛发帖EntitySets和的BindingSource和GetNewBindingList：

http://www.infragistics.com/community/forums/t/43526.aspx