C#对列表进行分组，然后从组中删除奇数编号的记录

var groupedRecords = from record in records
                     group record by record % 2 into grouped
                     select grouped;

foreach (var group in groupedRecords)
{
    if (group.Key == 1)
    {
        group.RemoveAll(record => record % 2 != 0);
    }
}

foreach (var group in groupedRecords)
{
    Console.WriteLine("Group: " + group.Key);
    foreach (var record in group)
    {
        Console.WriteLine("Record: " + record);
    }
}