ASP.NET Repeater User Control DataSource

Question

I have a user control that contains a repeater. It seems that data cannot be assigned to it's DataSource property, I have tried a few different data sources but the following error is displayed: (I have debugged it and there are data items in the datasource)

Object reference not set to an instance of an object

Here's the aspx for the repeater:

<asp:Repeater ID="repeater1" runat="server" >
    <HeaderTemplate>
        <ul>
    </HeaderTemplate>
        <ItemTemplate>
            <li>
                <%# Eval("Name") %>
            </li>
        </ItemTemplate>
    <FooterTemplate>
            </ul>
    </FooterTemplate>
</asp:Repeater>

I create an instance of the user control in the code behind of the file I want to display the repeater in - I can't type repeater1.DataSource and assign it in that page so I added an attribute to the user control which takes IEnumerable as the datasource.

Any ideas why this isn't working?

where do you assign the datasource to the repeater? If you cannot assign it from your page because the repeater control is inside a user control, create a method like SetDataSource in the user control and you pass a datasource to that method from your page and that method will assign it to the repeater. — Davide Piras

sll sll · Accepted Answer · 2011-09-29T12:23:25

You should do such things in the DataBind() method like shown below:

public override void DataBind()
{
   this.repeater.DataSource = ...
   this.repeater.DataBind();
   ...
}

So it will bind whilst parent page calling Page.DataBind() as well

Control.DataBind Method:

Use this method to bind data from a source to a server control. This method is commonly used after retrieving a dataset through a database query. Most controls perform data binding automatically, which means that you typically do not need to call this method explicitly.

ASP.NET Repeater User Control DataSource

2 Answers