Question

I am using a struct to pass to an unmanaged DLL as so –

[StructLayout(LayoutKind.Sequential)]
        public struct valTable
        {
            public byte type;
            public byte map;
            public byte spare1;
            public byte spare2;
            public int par;
            public int min;
            public byte[] name;
            public valTable()
            {
                name = new byte[24];
            }
        }

The code above will not compile because VS 2005 will complain that “Structs cannot contain explicit parameterless constructors”. In order to pass this struct to my DLL, I have to pass an array of struct’s like so valTable[] val = new valTable[281];

What I would like to do is when I say new, the constructor is called and it creates an array of bytes like I am trying to demonstrate because the DLL is looking for that byte array of size 24 in each dimension.

How can I accomplish this?

Answer 1

You can use a fixed size buffer – which I suspect you really want anyway, so as to get the data “inline” in the struct (rather than a reference to an array elsewhere).

public fixed byte name[24];

You’ll need to declare the struct as unsafe as well though.

Note that any “solution” which requires calling a static method or providing any kind of custom constructor will fail with your explicit goal of being able to create an array of these structs.