C# Definition:

    public struct MEMORY_BASIC_INFORMATION
    {
        public IntPtr BaseAddress;
        public IntPtr AllocationBase;
        public AllocationProtectEnum AllocationProtect;
        public IntPtr RegionSize;
        public StateEnum State;
        public AllocationProtectEnum Protect;
        public TypeEnum Type;
    }

User-Defined Field Types:

    public enum AllocationProtectEnum : uint
    {
        PAGE_EXECUTE = 0x00000010,
        PAGE_EXECUTE_READ = 0x00000020,
        PAGE_EXECUTE_READWRITE = 0x00000040,
        PAGE_EXECUTE_WRITECOPY = 0x00000080,
        PAGE_NOACCESS = 0x00000001,
        PAGE_READONLY = 0x00000002,
        PAGE_READWRITE = 0x00000004,
        PAGE_WRITECOPY = 0x00000008,
        PAGE_GUARD = 0x00000100,
        PAGE_NOCACHE = 0x00000200,
        PAGE_WRITECOMBINE = 0x00000400
    }

    public enum StateEnum : uint
    {
        MEM_COMMIT = 0x1000,
        MEM_FREE = 0x10000,
        MEM_RESERVE = 0x2000
    }

    public enum TypeEnum : uint
    {
        MEM_IMAGE = 0x1000000,
        MEM_MAPPED = 0x40000,
        MEM_PRIVATE = 0x20000
    }

Notes:

None.