How to get IntPtr from byte[] in C#

I want to pass a byte[] to a method takes a IntPtr Parameter in C#, is that possible and how?

Solution 1:

Another way,

GCHandle pinnedArray = GCHandle.Alloc(byteArray, GCHandleType.Pinned);
IntPtr pointer = pinnedArray.AddrOfPinnedObject();
// Do your stuff...
pinnedArray.Free();

Solution 2:

This should work but must be used within an unsafe context:

byte[] buffer = new byte[255];
fixed (byte* p = buffer)
{
    IntPtr ptr = (IntPtr)p;
    // do you stuff here
}

beware, you have to use the pointer in the fixed block! The gc can move the object once you are not anymore in the fixed block.

Solution 3:

Not sure about getting an IntPtr to an array, but you can copy the data for use with unmanaged code by using Mashal.Copy:

IntPtr unmanagedPointer = Marshal.AllocHGlobal(bytes.Length);
Marshal.Copy(bytes, 0, unmanagedPointer, bytes.Length);
// Call unmanaged code
Marshal.FreeHGlobal(unmanagedPointer);

Alternatively you could declare a struct with one property and then use Marshal.PtrToStructure, but that would still require allocating unmanaged memory.

Edit: Also, as Tyalis pointed out, you can also use fixed if unsafe code is an option for you