LINQ Any() argument versus parameter data type issues

Question

I have an object with a string-typed parameter called 'baan_cat_fam_code'. The code below is my attempt to find all items in the query that have a baan_cat_fam_code that exist in a generic string list called catFamCd.

query = query.Where(r => r.baan_cat_family_code.Any(s => catFamCode.Contains(s)));

The problem is that this won't compile - I get an error that states

"Argument type 'char' is not assignable to parameter type 'string'"

for some reason the predicate s is typed as char. So I append .ToString() to the argument in the .Contains method. However, when the code runs, I get the following exception thrown when the result of the query is bound to a listbox.

"The argument 'value' was the wrong type. Expected 'System.Char'. Actual 'System.String'."

This has got me scratching my head. Any assistance would be greatly appreciated.

Thanks!

Answer 1

The problem you're running into is that baan_cat_family_code is of type string which implements IEnumerable<char>. When you call Any it's essentially saying

• Is the predicate true for any char in this string

What you really want to be asking though is

• Is this string in the list catFamCode

Try the following which does the latter

query = query.Where(r => catFamCode.Contains(r.baan_cat_family_code));