If you have an integer that acts as a bitmask and could represent one or more values in a [Flags] enumeration, you can use this code to parse the individual flag values into a list:

for (var flagIterator = 0x1; flagIterator <= 0x80000000; flagIterator <<= 1)
{
    // Check to see if the current flag exists in the bit mask
    if ((intValue & flagIterator) != 0)
    {
        // If the current flag exists in the enumeration, then we can add that value to the list
        // if the enumeration has that flag defined
        if (Enum.IsDefined(typeof(MyEnum), flagIterator))
            ListOfEnumValues.Add((MyEnum)flagIterator);
    }
}

If you have an integer that acts as a bitmask and could represent one or more values in a [Flags] enumeration, you can use this code to parse the individual flag values into a list:

for (var flagIterator = 0; flagIterator < 32; flagIterator++)
{
    // Determine the bit value (1,2,4,...,Int32.MinValue)
    int bitValue = 1 << flagIterator;

    // Check to see if the current flag exists in the bit mask
    if ((intValue & bitValue) != 0)
    {
        // If the current flag exists in the enumeration, then we can add that value to the list
        // if the enumeration has that flag defined
        if (Enum.IsDefined(typeof(MyEnum), bitValue))
            Console.WriteLine((MyEnum)bitValue);
    }
}

Note that this assumes that the underlying type of the enum is a signed 32-bit integer. If it were a different numerical type, you'd have to change the hardcoded 32 to reflect the bits in that type (or programatically derive it using Enum.GetUnderlyingType())