Data Binding Nested DataList Controls

Whilst this example will show only one DataList within another, the example can be easily extended to any number of nested DataLists. Here are our 2 nested data list controls:

The above code shows that we have one label control in the outer datalist and one label control in the inner datalist which we will use to display our data. Our data source will be a simple string array:

The real work ofcourse is being done in our code-behind file:

First we fill our outer data list control (see method FillDataListOuter). Before we bind our outer data list we need to hook up the ItemCreated event handler as this is fired whenever a new item is created. We could have done this within Visual Studios designer view but i think this looks neater and consistent with the other method (FillDataListInner).

Within both the ItemCreated event handlers we first check that the ItemType is either an Item or an AlternatingItem since our controls are within the ItemTemplate.

(Although i haven't tried this, i dont suppose there would be any problem having a DataList nested within the <HeaderTemplate> of a DataList. The e.Item.ItemType we would then test for would be ListItemType.Header)

Anyhow, within the ItemCreated event handler of the outer data list we can now find our 2 controls one of which is the nested DataListInner and the other is the LabelOuterItem.

Similarly as before we fill our inner data list control (see method FillDataListInner). Before we bind out innner data list we need to hook up the ItemCreated event handler. Within this event handler we can access the label control (LabelInnerItem) of the inner data list.