C# Signature:

    [DllImport("kernel32.dll")]
    static extern int VirtualQueryEx(IntPtr hProcess, IntPtr lpAddress, out MEMORY_BASIC_INFORMATION lpBuffer, uint dwLength);
[DllImport("kernel32.dll")]
private static extern int VirtualQuery (
    ref UIntPtr lpAddress,
    ref MEMORY_BASIC_INFORMATION lpBuffer,
    int dwLength
);

VB.Net Signature:

    <DllImport("kernel32.dll")> _
    Public Shared Function VirtualQueryEx(Byval hProcess As IntPtr, Byval lpAddress As IntPtr, Byref lpBuffer As MEMORY_BASIC_INFORMATION, Byval dwLength As UInt32)
    End Function

User-Defined Types:

None.

C# User-Defined Types:

MEMORY_BASIC_INFORMATION

    [StructLayout(LayoutKind.Sequential)]
    public struct MEMORY_BASIC_INFORMATION
    {
    public IntPtr BaseAddress;
    public IntPtr AllocationBase;
    public uint AllocationProtect;
    public IntPtr RegionSize;
    public uint State;
    public uint Protect;
    public uint Type;
    }

Notes:

This code shows how to call the VirtualQuery function and how data structures must be prepared.

Tips & Tricks:

Please add some!

c# usefull Flags for MEMORY_BASIC_INFORMATION

Flags

    public enum AllocationProtect : 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
    }

Notes:

VirtualQueryEx returns 0 on failure.

Tips & Tricks:

Please add some!

Sample Code:

The following code demonstrates how to list all regions within a process' memory address.

class Class1

{

long MaxAddress = 0x7fffffff;
long address = 0;
do
{
     MEMORY_BASIC_INFORMATION m;
     int result = VirtualQueryEx(System.Diagnostics.Process.GetCurrentProcess().Handle, (IntPtr)address, out m, (uint)Marshal.SizeOf(typeof(MEMORY_BASIC_INFORMATION)));
     Console.WriteLine("{0}-{1} : {2} bytes result={3}", m.BaseAddress, (uint)m.BaseAddress + (uint)m.RegionSize - 1, m.RegionSize, result);
     if (address == (long)m.BaseAddress + (long)m.RegionSize)
     break;
     address = (long)m.BaseAddress + (long)m.RegionSize;
} while (address <= MaxAddress);
    [STAThread]
    static void Main(string[] args)
    {
        Memory memory = new Memory();
        memory.ShowMemory();

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        Console.Read();
    }

}

class Memory

{

    [StructLayout(LayoutKind.Sequential)]
    public struct SYSTEM_INFO {
        internal PROCESSOR_INFO_UNION p;
        public uint dwPageSize;
        public IntPtr lpMinimumApplicationAddress;
        public IntPtr lpMaximumApplicationAddress;
        public UIntPtr dwActiveProcessorMask;
        public uint dwNumberOfProcessors;
        public uint dwProcessorType;
        public uint dwAllocationGranularity;
        public ushort wProcessorLevel;
        public ushort wProcessorRevision;
    };

    [StructLayout(LayoutKind.Explicit)]
    public struct PROCESSOR_INFO_UNION
    {
        [FieldOffset(0)]internal uint dwOemId;
        [FieldOffset(0)]internal ushort wProcessorArchitecture;
        [FieldOffset(2)]internal ushort wReserved;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct MEMORY_BASIC_INFORMATION
    {
        public UIntPtr BaseAddress;
        public UIntPtr AllocationBase;
        public uint AllocationProtect;
        public IntPtr RegionSize;
        public uint State;
        public uint Protect;
        public uint Type;
    }

    SYSTEM_INFO system_info;
    MEMORY_BASIC_INFORMATION mbi;

    [DllImport("kernel32.dll")]
    private static extern int VirtualQuery (ref uint lpAddress,
        ref MEMORY_BASIC_INFORMATION lpBuffer,
        int dwLength
    );

    [DllImport("kernel32.dll")]
    private static extern void GetSystemInfo(
        [MarshalAs(UnmanagedType.Struct)] ref SYSTEM_INFO lpSystemInfo
    );

    public Memory()
    {
        system_info = new SYSTEM_INFO();
        mbi = new MEMORY_BASIC_INFORMATION();
    }

    public void ShowMemory()
    {
        int iSize;

        GetSystemInfo(ref system_info);
        Console.WriteLine("dwProcessorType: {0}", system_info.dwProcessorType.ToString());
        Console.WriteLine("dwPageSize: {0}", system_info.dwPageSize.ToString());

        if (VirtualQuery(ref system_info.dwPageSize,
            ref mbi,
            (int)System.Runtime.InteropServices.Marshal.SizeOf(mbi)) != 0
        )
        {
            Console.WriteLine("AllocationBase: {0}", mbi.AllocationBase);
            Console.WriteLine("BaseAddress: {0}", mbi.BaseAddress);
            Console.WriteLine("RegionSize: {0}", mbi.RegionSize);
        }
        else
        {
            Console.WriteLine("ERROR: VirtualQuery() failed.");
        }
    }

}

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