我在combobox中得到了一个静态值` [英] I am getting a static value in combobox`

问题描述

我正在运行一个程序，在该程序中，我从组合框"stn_list_"中选择电台.
但是每当我运行代码并从组合框中选择不同的站时..... i便获得了静态值，即"2ad"
请帮助...

i am running a program where i am selecting stations from the combobox ''stn_list_''
but when ever I run the code and i select different stations from the combobox.....i got the static value i.e ''2ad''
plz help......

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
       con.Open()
       stn_list.Items.Clear()


       Dim cmd4 As New SqlCommand("Select distinct stn from zonemaster", con)
       Dim dr4 As SqlDataReader = cmd4.ExecuteReader
       While (dr4.Read)
           stn_list.Items.Add(IIf(IsDBNull(dr4("stn")), "Null", dr4("stn")))
       End While
       con.Close()
   End Sub

   Protected Sub stn_list_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles stn_list.SelectedIndexChanged
       con.Open()
       party_list.Items.Clear()
       Dim stn As String
       stn = ""

       stn = stn_list.Text


       Dim cmd5 As New SqlCommand("Select  consignor from partymst where left(datatr,3)='" & stn & "'", con)
       Dim dr5 As SqlDataReader = cmd5.ExecuteReader
       While (dr5.Read)
           party_list.Items.Add(IIf(IsDBNull(dr5("consignor")), "Null", dr5("consignor")))
       End While
       con.Close()
   End Sub

推荐答案

您只需将代码从stn_list.text更改为stn_list.selectedValue即可，只要组合框的所有选定值为true即可更改为selected = false .

You just change the code from stn_list.text to stn_list.selectedValue on the form any selected value true of combobox to change with the selected = false.

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
       con.Open()
       stn_list.Items.Clear()


       Dim cmd4 As New SqlCommand("Select distinct stn from zonemaster", con)
       Dim dr4 As SqlDataReader = cmd4.ExecuteReader
       While (dr4.Read)
           stn_list.Items.Add(IIf(IsDBNull(dr4("stn")), "Null", dr4("stn")))
       End While
       con.Close()
   End Sub

   Protected Sub stn_list_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles stn_list.SelectedIndexChanged
       con.Open()
       party_list.Items.Clear()
       Dim stn As String
       stn = ""

       stn = stn_list.SelectedValue;


       Dim cmd5 As New SqlCommand("Select  consignor from partymst where left(datatr,3)='" & stn & "'", con)
       Dim dr5 As SqlDataReader = cmd5.ExecuteReader
       While (dr5.Read)
           party_list.Items.Add(IIf(IsDBNull(dr5("consignor")), "Null", dr5("consignor")))
       End While
       con.Close()
   End Sub

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