C# call WinApi?

Question

I am trying to call a WinAPI function DeviceIoControl in C# with code IOCTL_DISK_SET_DISK_ATTRIBUTES and pass struct SET_DISK_ATTRIBUTES. I am trying do it with thi

Answer 1

The original definition of SET_DISK_ATTRIBUTES:

typedef struct _SET_DISK_ATTRIBUTES {
  DWORD     Version;
  BOOLEAN   Persist;
  BYTE      Reserved1[3];
  DWORDLONG Attributes;
  DWORDLONG AttributesMask;
  DWORD     Reserved2[4];
} SET_DISK_ATTRIBUTES, *PSET_DISK_ATTRIBUTES;

makes use of BOOLEAN data type, which is defined as a synonym of unsigned char (1 byte), as opposed to BOOL that is a synonym of int (4 bytes).

C#'s bool is marshaled as BOOL by default.
You need to force it into one byte:

{
    ...
    [MarshalAs(UnmanagedType.I1)]
    public bool Persist;
    ...
}