Perehozhu s access na SQL server i GUI perepisyvaju pod vb.net
Voprosov t'ma... Po topikam iskal, no nichego ne nashol... naverno ploho iskal, t.k. vopros etot voznikal naberno u mnogih:

jest' forma "OrdersSQL", na nej 2 combo box. 1j: "SendTo", 2oj: "CustomerID". Dannyje berutsja s SQL servera tablica "Orders", a combo boxy zapolnjajutsja iz tablic: "Send Invoice" i "OurCustomers" sootvetstvenno.

Vopros prostoj: Kak vybiraja znachenije 1-go comba boxa vo 2om combobox otobrazhalis' tolko sootvetstvujushije znachenija.

Privozhu kod do chego sumel dodumatsja:
Na etom etape vsje rabotajet, no combo box 2 zapolnen vsjemi zapisjami bez filtracii v zamisimosti ot vybrannogo znachenija v combobox 1...

teper' mudrju s samoj filtracijej... nakopal, chto nuzhno stavit' etu samuju filtraciju na sobytije SelectedIndexChanged... verno li?

pytajus' zamutit' kod:

pojavljaetsja oshibka:
"An unhandled exception of type 'System.InvalidCastException' occurred in system.data.dll

Additional information: Object must implement IConvertible."

Proveril hod vypolnenija programmy. sobytije SelectedIndexChanged zapuskajetsja kazhdyj raz kogda vypolnjajetsja strochki
t.e. neskolkoraz... prichom pervyj raz proginjaja SelectedIndexChanged vsje prohodit bez oshibki, a 2j vylezajet vyshe ukazzannaja beda.

Izvinite, chto lainicej. i za dlinnoje pismo... no mozhet u kogo hvatit sil razobratsja s kodom, budu ochen' priznatelen za ljubuju pomosh. Mozhet podskazhite kak pravilno realizovyvat' svjazzanyje comboboxy? ja uzhe nemalo zaparilsja...

P.S. pishu pod windows.forms (izuchaju samostojatelno, 2 nedeli.. s nulja... ne skem posovetovatsja) jesli u kogo jest' pohozhaja gotovaja forma mozheno skinut' na nilsuha@mail.ru... spasibo.

budu iskat'... no... mozhet pri voznikshej vozmozhnosti poprobujete razobratsja... :) ?

Etot etap vrode proiden. Sdelal tak (mozhet komu prigoditsja):

Private Sub OrdersSQL_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

SqlDataAdapter1.Fill(DsOrdersSql2)
ComboBoxFill()
End Sub

Private Sub ComboBoxFill()
Dim cmdString As String
Dim connString As String = "data source=server2000;initial catalog=GriffinDB;integrated security=SSPI;persist security info=False;workstation id=SERVER2000;packet size=4096"
Dim myConnection As SqlClient.SqlConnection = New SqlClient.SqlConnection(connString)
myConnection.Open()

'+++++++++++++++ SendToComboBox ++++++++++++++++++++++

cmdString = "Select * from [Send invoice]"
Dim da1 As SqlClient.SqlDataAdapter = New SqlClient.SqlDataAdapter(cmdString, myConnection)
Dim DataView1 As New DataView()
Dim dataSet1 As DataSet = New DataSet()
da1.Fill(dataSet1, "[Send invoice]")

flag = False

With Me.SendTo
.DataSource = dataSet1.Tables("[Send invoice]")
.ValueMember = "ID"
.DisplayMember = "Send to"
End With

Me.SendTo.DataBindings.Add("selectedvalue", DsOrdersSql2, "Orders.Company")

'+++++++++++++++ CustomerComboBox ++++++++++++++++++++++

cmdString = "Select * from OurCustomers"

Dim da2 As SqlClient.SqlDataAdapter = New SqlClient.SqlDataAdapter(cmdString, myConnection)
da2.Fill(dataSet2, "OurCustomers")

With Me.CustomerID
.DataSource = dataSet2.Tables("OurCustomers")
.ValueMember = "ID"
.DisplayMember = "CompName"

End With

Me.CustomerID.DataBindings.Add("selectedvalue", DsOrdersSql2, "Orders.CustomerOrderID")

flag = True
myConnection.Close()
end sub

Private Sub SendTo_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SendTo.SelectedIndexChanged

If flag = True Then

Dim dv As DataView
dv = New DataView()
With dv
.Table = dataSet2.Tables("OurCustomers")
.RowFilter = "CompIndent = " & Me.SendTo.SelectedValue
.Sort = "CompName Asc"
End With

With Me.CustomerID
.DataSource = dv
.ValueMember = "ID"
.DisplayMember = "CompName"
End With
End If


End Sub



Teper' drugaja problema:
Delajem novyju zapis'... Vybirajem v pervom combobox(send to) ljuboje znachenije... vo vtorom comboboxe avtomaticheski pojavljajetsja pervoje iz otsortirovannyh znachenij, a nado chto by nichego ne vybirlos'(byla pustaja strochka), poka user sam ne vyberet. Kak eto sdelat'? Na selectedvaluechanged postavil me.customerid.selectedvalue = -1. Ne pomogajet... ili me.customerid.text = "" nichego ne pomogajet... POMOGITE... jesli sdes' voobshe mozhno naiti pomosh...