Question

All of this happens within the same user control so that shouldnt make a difference.

<asp:Repeater ID="rptActivity" runat="server" OnItemCreated="rptActivity_ItemCreated">
    <ItemTemplate>
        <div class="under-label">
            <div class="activity">
                <%#Eval("ActivityName")%>
                <input type="hidden" name="activityId" value='<%#Eval("ActivityId")%>' />
            </div>

            <div class="status">
                <asp:DropDownList ID="ddlStatuses" DataSourceID="SqlDataSource1"  DataTextField="Name" DataValueField="Id"  runat="server"></asp:DropDownList>
            </div>
            <div class="comment">
                <textarea name="comments" cols="35" rows="3" name="comment" style="float: left; margin: 0px 0px 0px 25px; font-family: Geneva, Arial, Helvetica, sans-serif;"><%#Eval("Comment")%></textarea>
            </div>
        </div>
    </ItemTemplate>
</asp:Repeater>

The i have the following code in the repeater’s itemcreated event:

 protected void rptActivity_ItemCreated(object sender, RepeaterItemEventArgs e)
        {
            var helper = (UpdateActivitiesHelper)e.Item.DataItem;

            DropDownList ddl = (DropDownList)FindControl("ddlStatuses");
            ddl.SelectedValue = helper.StatusId.ToString();
        }

and when i try to use ddl it throws NullReferenceException.

Any ideas?

Answer 1

Since your drop down list is inside the repeater, make sure you reference the DataItem to find the control.

Make sure to use e.Item.FindControl rather than Page.FindControl — Page.FindControl will not find this item because it will not recursively search the page

protected void rptActivity_ItemCreated(object sender, RepeaterItemEventArgs e)
{
    var helper = (UpdateActivitiesHelper)e.Item.DataItem;
    DropDownList ddl = (DropDownList)e.Item.FindControl("ddlStatuses");
    ddl.SelectedValue = helper.StatusId.ToString();
}