I am on chapter 5 of this book. I am having problem understanding the databinding Expression . I know that you can use Eval() when you know the datatype of the item to be bound.The problem is on the ArticleListing.ascx markup

Could anyone explain why he is casting the expression
Visible='<%#(bool)Eval("Approved")>' to bool(Because it is coming from the Articles table and the Approved is a bit field in that table).

I dont know whether am undestanding that correctly. For a label how can we set the Text=<%#Eval("ReleaseDate","{0:d}")> to a formatted datetime field? Why we dont need any casting here?


Any help would be greatly appreciated

Thank You

Eval always returns a string. So, when we are using Eval to set a text property, no cast is necessary, because the Text property of a control takes a string.

However, the Visible property of a control takes a boolean value. Eval("Approved") returns either the string "true" or the string "false". Therefore, that string output must be cast to a bool in order to use it to set the Visible property.

In this case, the string "true" would be cast to the Boolean value TRUE, and the string "false" would be cast to the Boolean value FALSE.

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