Massaging an array of dynamic sizes into a structure

Question

How can I define a structure with an array of dynamic size?

Is it correct?

struct MyStruc { public int len; [MarshalAs(UnmanagedType.LPArray, SizeParamIndex=0)] public int buf[]; } 

Answer 1

Assuming you need a structure containing a pointer to an array.

Declare the pointer to the array as IntPtr and manually create the contents of the array using Marshal.AllocHGlobal , Marshal.Copy , etc.

Assuming you want a variable-sized structure, not a structure containing an array pointer.

You cannot marshal a variable-sized structure using p / invoke. You have at least these two options:

• Divide the structure into two parameters.
• Marshal structures manually using Marshal.AllocHGlobal , Marshal.Copy , etc.