Thread: marshalling BLOBs to types

i am getting a byte[] array from a blob field in a database, and i need to convert it into an array of some other primitive type.

in unmanaged code, this is incredibly easy, but in .NET, it seems painful.

The Bitconverter is not a great option because there's no generic method and i don't know the types before the code executes.

any advice would be greatly appreciated.

i ended up going with a union and reflection.

Code:

        [StructLayout(LayoutKind.Explicit)]
        private class Union
        {
            [FieldOffset(0)]
            public bool _bool;
            [FieldOffset(0)]
            public byte _byte;
            [FieldOffset(0)]
            public sbyte _sbyte;
            [FieldOffset(0)]
            public char _char;

            [FieldOffset(0)]
            public Int16 _Int16;
            [FieldOffset(0)]
            public Int32 _Int32;
            [FieldOffset(0)]
            public Int64 _Int64;

            [FieldOffset(0)]
            public UInt16 _UInt16;
            [FieldOffset(0)]
            public UInt32 _UInt32;
            [FieldOffset(0)]
            public UInt64 _UInt64;

            [FieldOffset(0)]
            public double _double;
            [FieldOffset(0)]
            public float _float;

            [FieldOffset(0)]
            public decimal _decimal;

            public static implicit operator double(Union u)
            {
                return u._double;
            }

            public static implicit operator float(Union u)
            {
                return u._float;
            }

            public static implicit operator Int16(Union u)
            {
                return u._Int16;
            }
            public static implicit operator Int32(Union u)
            {
                return u._Int32;
            }
            public static implicit operator Int64(Union u)
            {
                return u._Int64;
            }

            public static implicit operator UInt16(Union u)
            {
                return u._UInt16;
            }
            public static implicit operator UInt32(Union u)
            {
                return u._UInt32;
            }
            public static implicit operator UInt64(Union u)
            {
                return u._UInt64;
            }
        }