Using DataGridViewRowCollection object in LINQ

I'd like to use a DataGridViewRowCollection in a LINQ expression using extension methods and lambda expressions. Unfortunately, the extension methods are for types IEnumerable<T>, which DataGridViewRowCollection doesn't implement. The funny thing is, I can use LINQ here with the SQL-like syntax:

IEnumerable<DataGridViewRow> lRows = from DataGridViewRow row in dgvGrid.Rows 
                                     select row;

After doing that, I can use LINQ extension methods:

foreach (DataGridViewRow lRow in lRows.Where(row => row.index > 4)) { ... }

Is there any way I can convert my DataGridViewRowCollection to an IEnumerab开发者_运维技巧le<> without using that long first statement? The same thing applies to DataGridViewCellCollection and DataGridViewColumnCollection.

ps. I'm using .net framework 3.5

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Yes, do this:

var rows = yourDataGridViewRowCollection
               .Cast<DataGridViewRow>()
               .Where(row => row.index > 4);

This uses the Enumerable.Cast extension method:

The Cast<TResult>(IEnumerable) method enables the standard query operators to be invoked on non-generic collections by supplying the necessary type information. For example, ArrayList does not implement IEnumerable<T>, but by calling Cast<TResult>(IEnumerable) on the ArrayList object, the standard query operators can then be used to query the sequence.