Reputation: 107
The PacketDotNet library defines a struct UInt128
. See:
How to convert this type into a simple byte array in C#?
Upvotes: 2
Views: 1277
Reputation: 2287
Using System.UInt128 (.NET 7). May not be relevant to PacketDotNet.UInt128.
This is similar to other solutions but includes a flag for unsigned values. This shouldn't add the extra 17th byte that @xanatos is referring to:
UInt128 number = UInt128.Parse("338288524927261089654164245681446711638");
byte[] myBytes = ((BigInteger)number).ToByteArray(isUnsigned: true);
Upvotes: 1
Reputation: 111850
Some funny tricks that you can do with newer .net core:
var ui = UInt128.MaxValue - 1;
{
var span = MemoryMarshal.Cast<UInt128, byte>(MemoryMarshal.CreateReadOnlySpan(ref ui, 1));
for (int i = 0; i < UInt128.SizeOf; i++)
{
Console.WriteLine(span[i]);
}
}
and/or given
[StructLayout(LayoutKind.Explicit)]
public struct UInt128Split
{
[FieldOffset(0)]
public UInt128 UInt128;
[FieldOffset(0)]
public ulong ULong1;
[FieldOffset(1)]
public ulong ULong2;
[FieldOffset(0)]
public uint UInt1;
[FieldOffset(4)]
public uint UInt2;
[FieldOffset(8)]
public uint UInt3;
[FieldOffset(12)]
public uint UInt4;
[FieldOffset(0)]
public byte Byte1;
[FieldOffset(1)]
public byte Byte2;
[FieldOffset(2)]
public byte Byte3;
[FieldOffset(3)]
public byte Byte4;
[FieldOffset(4)]
public byte Byte5;
[FieldOffset(5)]
public byte Byte6;
[FieldOffset(6)]
public byte Byte7;
[FieldOffset(7)]
public byte Byte8;
[FieldOffset(8)]
public byte Byte9;
[FieldOffset(9)]
public byte Byte10;
[FieldOffset(10)]
public byte Byte11;
[FieldOffset(11)]
public byte Byte12;
[FieldOffset(12)]
public byte Byte13;
[FieldOffset(13)]
public byte Byte14;
[FieldOffset(14)]
public byte Byte15;
[FieldOffset(15)]
public byte Byte16;
}
then
var ui = UInt128.MaxValue - 1;
{
ref UInt128Split rf = ref Unsafe.As<UInt128, UInt128Split>(ref ui);
Console.WriteLine(rf.UInt1);
Console.WriteLine(rf.UInt2);
Console.WriteLine(rf.UInt3);
Console.WriteLine(rf.UInt4);
Console.WriteLine(rf.ULong1);
Console.WriteLine(rf.ULong2);
// rf is the same as ui, so if we modify rf we modify ui!
Console.WriteLine(ui);
rf.ULong1 -= 11454;
Console.WriteLine(ui);
}
Upvotes: 2
Reputation: 107
I've also discovered myself another possibility:
public static unsafe byte[] GetBytesFromUInt128(this UInt128 value)
{
byte[] numArray = new byte[16];
fixed (byte* numPtr = numArray)
*(UInt128*) numPtr = value;
return numArray;
}
Upvotes: 3
Reputation: 787
It can be cast to a BigTnteger
then call ToByteArray()
as below.
var number = new Uint128();
((BigInteger)number).ToByteArray();
Upvotes: 3
Reputation: 20157
Looks like you assign it to a BigInteger
variable and use the ToByteArray()
method on that.
UInt128 n128 = 12345;
BigInteger bi = (BigInteger)n128;
byte[] ba = bi.ToByteArray();
Upvotes: 2