Umbraco: Cannot use lambda expression as argument to dynamically dispatched operation

19 November 2014

You’re probably doing something like this:

var pages = Umbraco
	.ContentAtRoot()
    .Children
	.OrderBy(p => p.SortOrder);

But the result of ContentAtRoot() is a dynamic, and you can’t sort a dynamic because the compiler doesn’t know any of its properties until its too late.

Really easy solution: use the Typed version of whatever Umbraco Helper call you were going to use! For example, here’s the above, fixed:

var pages = Umbraco
	.TypedContentAtRoot()
    .Children
	.OrderBy(p => p.SortOrder);

Likewise, you can use TypedContentAtXPath instead of ContentAtXPath and so on.

Have a great day :)

I write Umbraco solutions for Village Software