选定的下拉列表值始终为零

Question

I've two dropdown list boxes, Company and Vendor , in my window.. I'm loading the second one, Vendor, based on the value of first one, Company,

ddlVendorContact.DataSource = Facade.GetAllCompanyContactsByCompanyId(CompanyId);
ddlVendorContact.DataTextField = "FirstName";
ddlVendorContact.DataValueField = "Id";
ddlVendorContact.DataBind();

Now I want to combine the box selected values. So I wrote the following code.

Value = ddlCompany.SelectedValue + ddlVendorContact.SelectedValue;

But my problem is, when I'm selecting ddlCompany , that corresponding value is coming. But for ddlVendorContact , always 0 is coming. I don't know the reason. Can anyone suggest me the solution?

I'm using two ajaxs to load both ddl values.. Now, after analysis more, I came to know that based on Vendor, Contact is loading thru Ajax..

What I got now is, once ddlVendor ajax is executed, ddlVendorContact ajax is not executing..

ddlVendor.Attributes.Add("onChange", "return Company_OnChange('" + ddlVendor.ClientID + "','" + ddlVendorContact.ClientID + "','" + hdnSelectedVendorContact.ClientID + "','MemberID')");
ddlVendorContact.Attributes.Add("onChange", "return Contact_OnChange('" + ddlVendorContact.ClientID + "','" + hdnSelectedVendorContact.ClientID + "')");

Thanks & Regards,

Sakthi

Answer 1

The below snippet of code is a working example. Hope this helps.

Partial Class _Default Inherits System.Web.UI.Page

Sub BindList1()
    Dim a As New Dictionary(Of String, Int16)
    a.Add("sdsd", 1)
    a.Add("dfsd", 2)
    ddlList.DataSource = a
    ddlList.DataTextField = "key"
    ddlList.DataValueField = "value"
    ddlList.DataBind()
End Sub
Sub BindList2()
    If ddlList.SelectedValue = 1 Then
        Dim a As New Dictionary(Of String, Int16)
        a.Add("222", 1)
        a.Add("333", 2)
        ddlList2.DataSource = a

    Else
        Dim b As New Dictionary(Of String, Int16)
        b.Add("444", 1)
        b.Add("555", 2)
        ddlList2.DataSource = b

    End If
    ddlList2.DataBind()
End Sub

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
    If Not IsPostBack Then
        BindList1()
        BindList2()
    End If

End Sub

Protected Sub ddlList_SelectedIndexChanged(sender As Object, e As System.EventArgs) Handles ddlList.SelectedIndexChanged

    BindList2()
End Sub

Protected Sub btnSubmit_Click(sender As Object, e As System.EventArgs) Handles btnSubmit.Click
    Dim value = ddlList.SelectedValue + ddlList2.SelectedValue
End Sub

End Class