Question

I have a Serverside code in Java and client pages in .Net. Now I have to load a dropdown list in .Net from a serverside action class in Java. To do this, I created a asp dropdownlist as shown:

<asp:DropDownList ID="invoiceYear" runat="server" OnLoad='<%#GetYearRange()%>'  
    Width="150px" AutoPostBack="True">
</asp:DropDownList>

and I have a method GetYearRange in aspx.cs as shown:

[WebMethod]
public static string GetYearRange()
{
    System.Diagnostics.Debug.WriteLine("I am in");
    string strNewValue = "page=" + "" + "&rows=" + "" + "&sort=" + "" + "&order=" + ""; 
    string ss = ServerUtil.getServerString(strNewValue, "/invoice/invoice!getYearRange.action");
    System.Diagnostics.Debug.WriteLine("ss-->" + ss);
    return ss;
}

it is not going to that method. Please advice me how would I get the results from this method into my dropdownlist??

Answer 1

It should not be decorated with the [WebMethod] attribute, and you also are not calling the method correctly. If you want to have this bind itself with values you need to set its DataSource to a proper collection. If you are trying to set its current selected value you will need to set that specifically. The real question I would have is: What are you trying to do with this code?

If you are attempting to load the dropdownlist with values received from your service call:

protected void Page_Load(object sender, EventArgs e)
{
    // GetYearRange() will have to return at least a string[]
    // It would be better if it was a ListItem[] or a List<ListItem>
    invoiceYear.DataSource = GetYearRange();
    invoiceYear.DataBind();
}

If you already have it DataBound but you need to force the selected item to be the result of your service, you need to use the OnDataBound event:

<asp:DropDownList ID="invoiceYear" runat="server" OnDataBound="invoiceYear_DataBound"  
    Width="150px" AutoPostBack="True">
</asp:DropDownList>

...

protected void invoiceYear_DataBound(object sender, EventArgs e)
{
     invoiceYear.SelectedValue = GetYearRange();
}