如何通过循环浏览vb.net中的组合框项来选择组合框上的特定值

Question

我的vb.net应用程序中有一个窗体，用于获取关于返回的库存的数据。该表单包含两个组合框。一个名为combobox5的包含发票号码，另一个名为combobox3包含派对代码。两个组合框都是使用sqldataadapter预加载的。

现在我想要的是在combobox5中更改发票号码时更改combobox3中的派对代码。进一步详细阐述，当股票发行时，派代码与发票号码一起存储以跟踪哪一方是股票发行。现在，当股票被退回时，我想跟踪哪一方已经退回股票，我希望当发票号码被更改时应该自动选择派代码，并且它应该是针对该特定发票号码存储在数据库中的内容。 ...

我用下面的代码这样做：

Private Sub ComboBox5_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ComboBox5.SelectedIndexChanged 

    ' defines a new connection to the database 
    Dim con As New SqlConnection("Data Source=TAHA;Initial Catalog=ADT;Integrated Security=True") 
    con.Open() 


    If ComboBox5.SelectedIndex = 0 Then 


     ComboBox3.Enabled = True 
     If Not ComboBox3.Items.Count = 0 Then 

      ComboBox3.SelectedIndex = 0 
     End If 
    Else 

     Me.ComboBox3.Enabled = False 
     Me.ComboBox3.BackColor = Color.White 
     Me.ComboBox3.ForeColor = Color.Black 

     Dim invoices As New SqlCommand("select invoice_no, party_code from Outgoing_Invoice group by invoice_no, party_code", con) 
     Dim reader As SqlDataReader = invoices.ExecuteReader 

     While reader.Read 

      Dim cnt, i As Integer 

      cnt = Me.ComboBox3.Items.Count 

      If Me.ComboBox5.SelectedItem.ToString.Trim = reader("invoice_no").ToString.Trim Then 

       If Not cnt = 0 Then 


        For i = 0 To cnt - 1 
         If Me.ComboBox3.Items.Item(i).ToString.Trim.Contains(reader("party_code").ToString.Trim) Then 'here i have also used equals instead of contains but that too doesn't work 
          Me.ComboBox3.SelectedIndex = i 
          Exit For 
         End If 
        Next 

       End If 
      End If 
     End While 

     reader.Close() 



    End If 
    con.Close() 


End Sub 

Answer 1

您要使用的SelectionChangeCommitted事件，而不是因为当编程方式更改选定的SelectedIndexChanged也将被解雇。