‫پشتیبانی از تولید UUID v7 در دات‌نت 9

var guid = Guid.NewGuid(); // v4 UUID

Guid uuidV7 = Guid.CreateVersion7(); // uses Datetime.UtcNow

var guidWithTimestamp = Guid.CreateVersion7(DateTimeOffset.UtcNow);

var guid = Guid.CreateVersion7();
Console.WriteLine($"V{guid.Version}: {guid}");

+------------------+---------------+----------------------+
| 48-bit timestamp | 12-bit random |    62-bit random     |
+------------------+---------------+----------------------+

public static class GuidV7
{
    private const byte Variant10xxMask = 0xC0;
    private const byte Variant10xxValue = 0x80;
    private const ushort VersionMask = 0xF000;
    private const ushort Version7Value = 0x7000;

    public static Guid Create() => Create(DateTimeOffset.UtcNow);

    public static Guid Create(DateTimeOffset timestamp)
    {
        var unixTsMs = timestamp.ToUnixTimeMilliseconds();
        ArgumentOutOfRangeException.ThrowIfNegative(unixTsMs, nameof(timestamp));

        var result = Guid.NewGuid().ToByteArray();

        var a = result.AsSpan(..4);
        BitConverter.TryWriteBytes(a, (int)(unixTsMs >> 16));
        var b = result.AsSpan(4..6);
        BitConverter.TryWriteBytes(b, (short)unixTsMs);
        var c = result.AsSpan(6..8);
        BitConverter.TryWriteBytes(c, (short)((BitConverter.ToInt16(c) & ~VersionMask) | Version7Value));
        var d = result.AsSpan(8..9);
        d[0] = (byte)((d[0] & ~Variant10xxMask) | Variant10xxValue);
        return new Guid(result);
    }
}

for (int i = 0; i < 5; i++)
{
    var guid = Guid.NewGuid();
    Console.WriteLine($"V{guid.Version}: {guid}");
}
Console.WriteLine();
for (int i = 0; i < 5; i++)
{
    var guid = Guid.CreateVersion7();
    Console.WriteLine($"V{guid.Version}: {guid}");
}

V4: 0557b321-abcf-4390-abee-4b8fbf93ff34
V4: 21a98165-af1e-477e-9dee-7eb9c79e6c77
V4: 7dbbf973-c55a-4917-87a5-95c16f356262
V4: b13892f2-334f-409a-b9de-d90dea21eed4
V4: 52dc44f7-76e0-4689-a5e6-1a0f1c5f37a3

V7: 01917bbe-d973-7beb-a813-106fcb4eff98
V7: 01917bbe-d973-703c-8365-b7596740ac82
V7: 01917bbe-d973-7234-a580-5f07730a3ad7
V7: 01917bbe-d973-7751-b8ba-bb73afab4a5d
V7: 01917bbe-d973-7d36-9be0-2e6317919153

public static Guid CreateCryptographicallySecureGuid()
{
    using (var provider = System.Security.Cryptography.RandomNumberGenerator.Create())
    {
        var bytes = new byte[16];
        provider.GetBytes(bytes);

        return new Guid(bytes);
    }
}