Dapper MiniExcel Newtonsoft.Json System.Data.SqlClient Dapper MiniExcelLibs Newtonsoft.Json System.Data System.Diagnostics System.Linq.Expressions System.Text System.Text.RegularExpressions System.Threading System.Transactions System.Xml System.Xml.Linq System.Xml.XPath // 【LINQ】Deferred Execution void Main() { var input = GetFooData(); { var output = input.Skip(10).Take(5); //console output : 0..14 output.Count(); } { var output = input.ToList().Skip(10).Take(5); //console output : 0..99 output.Count(); } } IEnumerable GetFooData() { for (int i = 0; i < 100; i++) { Console.WriteLine(i); yield return i; } }