1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Threading.Tasks; const string TEXT = @"1 2 3 4 5" ; var file = new TextFile( "file.txt" ); await file.Create(TEXT); var sum = 0L; await foreach ( var line in file.Read()) { sum += line .Split( ' ' , StringSplitOptions.RemoveEmptyEntries) .Select( int .Parse) .Where(x => x % 2 == 1) .Sum(); } Console.WriteLine(sum); internal readonly record struct TextFile( string FilePath) { public async Task Create( string text) => await File.WriteAllTextAsync(FilePath, text); public async IAsyncEnumerable< string > Read() { using var stream = new StreamReader(FilePath, new FileStreamOptions { Access = FileAccess.Read, Mode = FileMode.Open, Share = FileShare.Read, Options = FileOptions.Asynchronous | FileOptions.SequentialScan, }); while (!stream.EndOfStream) { yield return await stream.ReadLineAsync(); } } } |