Cross Postback from Masterpage

Question

I have a textbox used to search for products. This textbox is placed in the site's masterpage. However, I'm getting a null error for the frmSearch value once posted back.

masterpage search:

<asp:TextBox ID="frmSearch" runat="server" CssClass="searchbox"></asp:TextBox>
<asp:LinkButton ID="searchGo" CssClass="searchbutton" PostBackUrl="search.aspx"  runat="server">GO</asp:LinkButton>

search.aspx pageload:

if (PreviousPage != null && PreviousPage.IsCrossPagePostBack)
        {
            Page previousPage = PreviousPage;
            TextBox tbSearch = (TextBox)PreviousPage.FindControl("frmSearch");
            searchValue.Text = for tbSearch.Text;
        }

Where am I going wrong?

Answer 1

frmSearch doesn't exist on your PreviousPage. It exists on the Master page of PreviousPage.

If you change the following line to include .Master , it should pull that text box.

TextBox tbSearch = (TextBox)PreviousPage.Master.FindControl("frmSearch");