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How do I iterate over a List<KeyValuePair<>> and update the value of my KeyValuePair<>?

jxbma asked
Last Modified: 2013-11-11
I have a List<T> defined below.
List<KeyValuePair<MyClass, decimal>> tciList = new List<KeyValuePair<MyClass, decimal>>();
int myValue = 12;

This is an in memory list, and I'd like to update values based on a selection criteria.

Currently, I can write a LINQ query that returns all the values based on that criteria.

TAKE #1:
foreach (var item in from v in tciList .AsEnumerable()
                               where (v.Key as MyClass).DiscountID == (int)myValue
                               select v)
         item.Value = 100;

TAKE #2:
foreach (KeyValuePair<MyClass, decimal>item in tciList.AsEnumerable())
         item.Value = 100;

In either case, I get the following error:

Error      404      
Property or  Indexer  
cannot be assigned to -- it is read only

What's going on here? Is there a copy of the list get returned for the iteration?
I googled and saw reference to some changes between Beta 2 and Beta 3 which after which folks started
encountering the error.

How do I iterate over the list and make changes to values in my KeyValuePair<>?

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