Hallo Mike,
wenn ich es recht verstehe ist Dein Problem die log.
Verknupfung zweier DataTables (Master / Detail).
Hier mal ein einfaches Beispiel mit einer Combobox (Master)
und einer ListBox (Detail).
Mit jeder Auswahl in der ComboBox (Master) werden in der
darunter liegenden Listbox die zur Auswahl gehörenden
Detaildatensätze angezeigt.
Kopiere den nachfolgenden Code in ein leeres Formmodul (Form1.vb)
' / / / Code in Formmodul Form1.vb
Public Class Form1
Private WithEvents cboMaster As ComboBox
Private WithEvents lstDetail As ListBox
Private mDS As DataSet
Private mDTmaster As DataTable
Private mDVmaster As DataView
'Private WithEvents mCMmaster As CurrencyManager
Private mDTdetail As DataTable
Private mDVdetail As DataView
Private Sub Form1_Load _
(ByVal sender As System.Object, _
ByVal e As System.EventArgs _
) Handles MyBase.Load
CreateControls()
CreateData()
With cboMaster
.DataSource = mDVmaster
.DisplayMember = _
mDTmaster.Columns(1).ColumnName
.ValueMember = _
mDTmaster.Columns(0).ColumnName
End With
End Sub
Private Sub CreateControls()
Dim Fnt As New Font("Arial", 12)
cboMaster = New ComboBox
With cboMaster
.Name = "cboMaster"
.Font = Fnt
.SetBounds _
(10, 15, _
Me.ClientSize.Width - 20, _
.Height)
.Anchor = _
AnchorStyles.Left Or _
AnchorStyles.Top Or _
AnchorStyles.Right
.DropDownStyle = _
ComboBoxStyle.DropDownList
End With
Me.Controls.Add(cboMaster)
lstDetail = New ListBox
With lstDetail
.Name = "lstDetail"
.Font = Fnt
.SetBounds _
(10, _
cboMaster.Bottom + 15, _
cboMaster.Width, _
Me.ClientSize.Height - (cboMaster.Bottom + 20))
.Anchor = _
AnchorStyles.Left Or _
AnchorStyles.Top Or _
AnchorStyles.Right Or _
AnchorStyles.Bottom
End With
Me.Controls.Add(lstDetail)
End Sub
Private Sub CreateData()
Dim i As Integer
Dim k As Integer
Dim DR As DataRow
'Dim DC As DataColumn
Dim Animals As New List(Of String())
Dim Buffer() As String
mDS = New DataSet("mDS")
Dim Groups() As String = _
New String() _
{"Säugetier", "Vogel", "Fisch", "Insekt"}
Animals.Add _
(New String() _
{"Hund", "Katze", "Maus"})
Animals.Add _
(New String() _
{"Adler", "Dohle", "Schwalbe", "Elster"})
Animals.Add _
(New String() _
{"Karpfen", "Hering", "Makrele", "Dorsch"})
Animals.Add _
(New String() _
{"Fliege", "Stechmücke", "Hummel", "Biene"})
mDTdetail = New DataTable
With mDTdetail
.TableName = "mDTdetail"
.Columns.Add("ID", GetType(Integer))
.Columns.Add("FKey", GetType(Integer))
.Columns.Add("Tier", GetType(String))
End With
' Primärschlüssel für mDTdetail über zwei Felder (ID u. FKey)
Dim Cols(1) As DataColumn
Cols(0) = mDTdetail.Columns(0)
Cols(1) = mDTdetail.Columns(1)
Dim UC As UniqueConstraint = _
New UniqueConstraint("PKd", Cols)
mDTdetail.Constraints.Add(UC)
mDTmaster = New DataTable
With mDTmaster
.TableName = "mDTmaster"
.Columns.Add("ID", GetType(Integer))
.Columns.Add("Gruppe", GetType(String))
For i = 0 To Groups.GetUpperBound(0)
DR = .NewRow
DR.Item("ID") = i
DR.Item("Gruppe") = Groups(i)
.Rows.Add(DR)
Buffer = Animals(i)
For k = 0 To Buffer.GetUpperBound(0)
DR = mDTdetail.NewRow
DR.Item("ID") = k
DR.Item("FKey") = i
DR.Item("Tier") = Buffer(k)
mDTdetail.Rows.Add(DR)
Next
mDTdetail.AcceptChanges()
Next
.AcceptChanges()
End With
' Primärschlüssel für mDTMaster (Feld ID)
mDTmaster.Constraints.Add _
(New UniqueConstraint _
("PKm", mDTmaster.Columns("ID"), True))
mDS.Tables.Add(mDTmaster)
mDS.Tables.Add(mDTdetail)
mDS.Relations.Add _
("RelMD", _
mDTmaster.Columns("ID"), _
mDTdetail.Columns("FKey"), _
True)
mDVmaster = mDTmaster.DefaultView
End Sub
Private Sub cboMaster_SelectedIndexChanged _
(ByVal sender As Object, _
ByVal e As System.EventArgs _
) Handles cboMaster.SelectedIndexChanged
Dim DRV As DataRowView
DRV = DirectCast(cboMaster.SelectedItem, DataRowView)
mDVdetail = DRV.CreateChildView(mDS.Relations("RelMD"))
lstDetail.DataSource = mDVdetail
With lstDetail
.DataSource = mDVdetail
.DisplayMember = mDTdetail.Columns(2).ColumnName
End With
End Sub
End Class
' \ \ \ E N T E
Nach dem Programmstart siehst Du die Form1 mit einer
ComboBox und einer darunter angeordneten Listbox.
Nach Auswahl eines Eintrages in der ComboBox werden
in der Listbox die zugehörigen Details sichtbar.
Gruß aus St.Georgen
Peter Götz
www.gssg.de (mit VB-Tipps u. Beispielprogrammen)
