Question

//The collection “fields” contain a set of rows with a column “FieldId”

DataRow[] fields = GetFields();

//This dictionary contains a set of key value pairs. keys represent FieldId’s and values represent OrderId’s

Dictionary<string, int> orders = new Dictionary<string, int>();
orders = LoadOrders();

I need to reorder the “fields” collection in the order of OrderId’s in the dictionary. The dictionary should be used as a cross reference to look up the FieldId and get the OrderId.

Sample data in fields:

Books
Movies
Electronics

Sample data in orders:

<Books, 2>
<Movies, 3>
<Electronics, 1>

The output by reordering the "fields" should be :

Electronics
Books
Movies

If anyone has any ideas on this, can you please share? Thank you.

Answer 1

This should work:

var res = fields.OrderBy(x => orders[x.Field<string>("FieldId")]).ToArray();

Or, if you prefer an in-place sort:

Array.Sort(fields,
          (a,b) => orders[a.Field<string>("FieldId")]
                   .CompareTo(orders[b.Field<string>("FieldId")]));

Of course you need to be sure that orders dictionary contains all the values present in fields collection.