C# Signature:

[DllImport("kernel32.dll")]
public static extern int VirtualQueryEx(
     IntPtr handle,
     IntPtr adress,
     out ProcessQueryInformation processQuery,
     uint length
);

User-defined structures

    public enum ProtectionConstant
    {
        Execute = 0x10,
        ExecuteAndRead = 0x20,
        ExecuteAndReadAndWrite = 0x40,
        ExecuteWithWriteCopy = 0x80,
        NoAccess = 0x01,
        ReadOnly = 0x02,
        ReadAndWrite = 0x04,
        WriteCopy = 0x08,
        Guard = 0x100,
        NoCache = 0x200,
        WriteCombine = 0x400,
    }

    public enum QueryState
    {
        Commit = 0x1000,
        Free = 0x10000,
        Reserved = 0x2000,
    }

    public enum MemoryType
    {
        Image = 0x1000000,
        Mapped = 0x40000,
        Private = 0x20000,
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct ProcessQueryInformation
    {
        public IntPtr BaseAdress; // void*
        public IntPtr AllocationBase; // void*
        public ProtectionConstant AllocationProtect; // DWORD
        public uint RegionSize; // size_t
        public QueryState State; // DWORD
        public ProtectionConstant Protect; // DWORD
        public MemoryType Type; // DWORD
    }