C++ Bit Fields implementation in C#

Vini Deep

Hi, I have a structure declared with bit fields in one of the C++ dll I am calling in my c# application. How can I change it to C# type struct?

typedef unsigned int UINT32;
 

typedef struct DEV_TYPE 
{
  UINT32 ReadCdR        :1;
  UINT32 ReadCdRw       :1;
  UINT32 ReadDvdRom     :1;
  UINT32 ReadDvdRam     :1;
  UINT32 ReadDvdMinusR  :1;
  UINT32 ReadDvdMinusRw :1;
  UINT32 ReadDvdPlusR   :1;
  UINT32 ReadDvdPlusRw  :1;
  UINT32 WriteCdR       :1;
  UINT32 WriteCdRw      :1;
  UINT32 Reserved0      :1;
  UINT32 WriteDvdRam    :1;
  UINT32 WriteDvdMinusR :1;
  UINT32 WriteDvdMinusRw:1;
  UINT32 WriteDvdPlusR  :1;
  UINT32 WriteDvdPlusRw :1;
  UINT32 TapeDrive      :1;
  UINT32 Reserved       :15;
} DEV_TYPE;

I have read in MSDN that C# does not support bit fields. Is there any method to implement this structure in C#? Pls help.. Thanks Vini

A Wegierski

Use BitArray(sealed) or BitVector32 or try to create new class using uint and next define set/get properties: private uint a=0; public uint A { set { A=value; } get { return a; } } public uint A0 { set { a &= 0xFEU; if(value>0) a+=0x1U; } get { return a & 0x01U; } } ... Hi, AW

Tim Kohler

Your C# code could just pass/receive a uint from the .dll. Just use the bitwise operators in C# to set up or read the various bits. You'd have to define your bits differently and wouldn't really use a 'bit field' but you'd get the same effect of storing several bools in a single 32 bit variable. i.e. C++: const UINT32 ReadCdR = 0x00000001; const UINT32 ReadCdRw = 0x00000002; const UINT32 ReadDvdRom = 0x00000004; ... const UINT32 TapeDrive = 0x0000FFFF; bool DoSomething(UINT32 devType) { if (devType & ReadCdR) ... } C#: private static uint ReadCdR = 0x00000001; private static uint ReadCdRw = 0x00000002; private static uint ReadDvdRom = 0x00000004; ... private static uint TapeDrive = 0x0000FFFF; public static CallSomethingInDll() { uint val = ReadCdR | ReadCdRw | TapeDrive; bool ret = CPPWrapperOrManagedClass.DoSomething(val); }

Vini Deep

I got it with BitVector32 BitVector32.CreateSection Method and get/set methods. Thanks :rose: Vini

leppie

O lord, another programmer trying to be clever without knowing how to use bit masks (not you). This is what it should look like both sides...

[Flags]
enum DEV_TYPE // wow what do u know? sizeof(DEV_TYPE) == 32
{
ReadCdR =1 << 0,
ReadCdRw =1 << 1,
ReadDvdRom =1 << 2,
ReadDvdRam =1 << 3,
ReadDvdMinusR =1 << 4,
ReadDvdMinusRw =1 << 5,
ReadDvdPlusR =1 << 6,
ReadDvdPlusRw =1 << 7,
WriteCdR =1 << 8,
WriteCdRw =1 << 9,
//Reserved0 =1 << 10,
WriteDvdRam =1 << 11,
WriteDvdMinusR =1 << 12,
WriteDvdMinusRw=1 << 13,
WriteDvdPlusR =1 << 14,
WriteDvdPlusRw =1 << 15,
TapeDrive =1 << 16,
}

top secret AdvancedTextBox

A Wegierski

C# has constants too Hi, AW

Member 3630266

Hi Vini, I am also having the same problem using bit fields in C#. Is it possible for you to post ur sample code? Thanks, - Prerna