C# Signature:

[DllImport("kernel32.dll")]
private static extern UIntPtr VirtualQuery (
    UIntPtr lpAddress,
    out MEMORY_BASIC_INFORMATION lpBuffer,
    UIntPtr dwLength
);

User-Defined Types:

None.

Notes:

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

Tips & Tricks:

Please add some!

Sample Code:

class Class1
{
    [STAThread]
    static void Main(string[] args)
    {
        Memory memory = new Memory();
        memory.ShowMemory();

        Console.Read();
    }
}

class Memory
{
    [StructLayout(LayoutKind.Sequential)]
    public struct SYSTEM_INFO {
        internal PROCESSOR_INFO_UNION p;
        public uint dwPageSize;
        public UIntPtr lpMinimumApplicationAddress;
        public UIntPtr 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 UIntPtr RegionSize;
        public uint State;
        public uint Protect;
        public uint Type;
    }

    SYSTEM_INFO system_info;
    MEMORY_BASIC_INFORMATION mbi;

    [DllImport("kernel32.dll")]
    private static extern UIntPtr VirtualQuery (
        UIntPtr lpAddress,
        out MEMORY_BASIC_INFORMATION lpBuffer,
        UIntPtr dwLength
    );

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

    public void ShowMemory()
    {
        int iSize;

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

        if (VirtualQuery((UIntPtr)system_info.dwPageSize,
                 out mbi,
                 (UIntPtr)System.Runtime.InteropServices.Marshal.SizeOf<MEMORY_BASIC_INFORMATION>()) != 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.");
        }
    }
}

Alternative Managed API:

Do you know one? Please contribute it!

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).