How can I get the total physical memory in C#?

I am using the GlobalMemoryStatusEx function to retrieve information about memory, but this function doesn't work correctly. It returns 0 for all properties. I don't think this function works in my Windows 7 environment.

    [StructLayout(LayoutKind.Sequential)]
    internal struct MEMORYSTATUSEX
    {
        internal uint dwLength;
        internal uint dwMemoryLoad;
        internal ulong ullTotalPhys;
        internal ulong ullAvailPhys;
        internal ulong ullTotalPageFile;
        internal ulong ullAvailPageFile;
        internal ulong 开发者_高级运维ullTotalVirtual;
        internal ulong ullAvailVirtual;
        internal ulong ullAvailExtendedVirtual;
    }
    [return: MarshalAs(UnmanagedType.Bool)]
    [DllImport("Kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    internal static extern bool GlobalMemoryStatusEx(ref MEMORYSTATUSEX lpBuffer);

    private void btnGlobalMemoryStatusEX_Click(object sender, EventArgs e)
    {
        MEMORYSTATUSEX statEX = new MEMORYSTATUSEX();
        GlobalMemoryStatusEx(ref statEX);

        double d = (double)statEX.ullTotalPhys;
    }

Can anybody tell me where I went wrong with wrong code?

I find my mistake from: http://www.pinvoke.net/default.aspx/kernel32/GlobalMemoryStatusEx.html

I Changed

internal static extern bool GlobalMemoryStatusEx(ref MEMORYSTATUSEX lpBuffer);

To

static extern bool GlobalMemoryStatusEx([In, Out] MEMORYSTATUSEX lpBuffer);

and changed

GlobalMemoryStatusEx(ref statEX);

To

GlobalMemoryStatusEx(statEX);

It work correctly. Tanks

How about:

My.Computer.Info.TotalPhysicalMemory
My.Computer.Info.AvailablePhysicalMemory

If c# you can:

Reference the Microsoft.VisualBasic assembly. Then import Microsoft.VisualBasic.Devices namespace.
And finally use ComputerInfo to get the total physical memory.

int bytesPerMebibyte = (1 << 20);  // http://physics.nist.gov/cuu/Units/binary.html
ComputerInfo myCompInfo = new ComputerInfo();
string physicalMemory = "Physical Memory: "
    + (myCompInfo.TotalPhysicalMemory / bytesPerMebibyte) + " MB";

you can use this templates:

long memory = Process.GetCurrentProcess().PeakVirtualMemorySize64;

And another properties with names Peak*64

You forgot to set statEX.dwLength before calling GlobalMemoryStatusEx.

MEMORYSTATUSEX statEX = new MEMORYSTATUSEX();
statEX.dwLength = (uint)Marshal.SizeOf(typeof(MEMORYSTATUSEX));
GlobalMemoryStatusEx(ref statEX);