C# – LINQ: How to declare IEnumerable[AnonymousType]


This is my function:

    private IEnumerable<string> SeachItem(int[] ItemIds)
        using (var reader = File.OpenText(Application.StartupPath + @"\temp\A_A.tmp"))
            var myLine = from line in ReadLines(reader)
                         where line.Length > 1
                         let id = int.Parse(line.Split('\t')[1])
                         where ItemIds.Contains(id)
                         let m = Regex.Match(line, @"^\d+\t(\d+)\t.+?\t(item\\[^\t]+\.ddj)")
                         where m.Success == true
                         select new { Text = line, ItemId = id, Path = m.Groups[2].Value };
            return myLine;

I get a compile error,because "myLine" is not a IEnumerable[string] and I don't know how to write IEnumerable[Anonymous]

"Cannot implicitly convert type 'System.Collections.Generic.IEnumerable[AnonymousType#1]' to 'System.Collections.Generic.IEnumerable[string]'"

Best Solution

You cannot declare IEnumerable<AnonymousType> because the type has no (known) name at build time. So if you want to use this type in a function declaration, make it a normal type. Or just modify your query to return a IENumerable<String> and stick with that type.

Or return IEnumerable<KeyValuePair<Int32, String>> using the following select statement.

select new KeyValuePair<Int32, String>(id, m.Groups[2].Value)