Databinding methods such as Eval(), XPath(), and Bind() can only be used in the context of a databound control

See more:

DropDownList

SelectedValue

Hello please help me
I have tow Drop Down-list Control which the are Bind to Province TB and District TB
Now when user redirected with Query string to Edit page Both DropDown-list Displayed the Province Name and District Name of that user which redirected in this page,

But the Problem is when user want to select a new Province name from Dropdownlist for Update there province or District, when Drop Downlist Province go to AutoPostBack or refresh this error happen in this line

Line 115: <asp:DropDownList ID="DropDistrict" runat="server" SelectedValue='<%# Eval("DistrictID") %>'

my cod

</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Province" SortExpression="ProvinceID">
    <ItemTemplate>

        <asp:DropDownList ID="DropProvince" runat="server"
          Height="26px"  Width="150px"  AppendDataBoundItems="True" DataSourceID="SqlDataSource1" DataTextField="PName_en" DataValueField="P_ID" SelectedValue='<%# Eval("ProvinceID") %>' OnSelectedIndexChanged="DropProvince_SelectedIndexChanged1"  AutoPostBack="True">
        </asp:DropDownList>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:SchoolConnectionString %>" SelectCommand="SELECT [P_ID], [PName_en] FROM [Province]"></asp:SqlDataSource>
    </ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="District" SortExpression="DistrictID">
    <ItemTemplate>

        <asp:DropDownList ID="DropDistrict" runat="server" SelectedValue='<%# Eval("DistrictID") %>'
            Height="26px" Width="150px"  DataSourceID="SqlDataSource11" DataTextField="DName_en" DataValueField="D_ID" >
        </asp:DropDownList>
        <asp:SqlDataSource ID="SqlDataSource11" runat="server" ConnectionString="<%$ ConnectionStrings:SchoolConnectionString %>" SelectCommand="SELECT [D_ID], [DName_en], [ProvinceID] FROM [District] WHERE ([ProvinceID] = @ProvinceID)">
            <SelectParameters>
                <asp:ControlParameter ControlID="DropProvince" Name="ProvinceID" PropertyName="SelectedValue" Type="Int32" />
            </SelectParameters>
        </asp:SqlDataSource>

    </ItemTemplate>
</asp:TemplateField>