http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemwebuidatabinderclassevaltopic1.asp?frame=truede skriver det godt nok selv
citat :
"Remarks
While this method is automatically called when you create data bindings in a RAD designer, you can also use it declaratively if you want to simplify the casting to a text string to be displayed on a browser. To do so, you must place the <%# and %> tags, which are also used in standard ASP.NET data binding, around the data-binding expression.
This method is particularly useful when binding data against controls that are in a templated list.
CAUTION Since this method performs late-bound evaluation, using reflection, at runtime, it can cause performance to noticeably slow compared to standard ASP.NET data-binding syntax.
For any of the list Web controls, such as DataList, DataGrid, or Repeater, the container parameter should be Container.DataItem. If you are binding against the page, the container parameter should be Page
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