Parameter in C#

Question

When I want get total value of memory in C# I found a kernel32 function in MSDN to invoke data from system. MSDN declare function this way:

[return: MarshalAs(Un         


        

Answer 1

The following definition works (define the MEMORYSTATUSEX as a class):

[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GlobalMemoryStatusEx(MEMORYSTATUSEX lpBuffer);

[StructLayout(LayoutKind.Sequential)]
public sealed class MEMORYSTATUSEX {
  public uint dwLength = (uint)Marshal.SizeOf(typeof(MEMORYSTATUSEX));
  public uint dwMemoryLoad;
  public ulong ullTotalPhys;
  public ulong ullAvailPhys;
  public ulong ullTotalPageFile;
  public ulong ullAvailPageFile;
  public ulong ullTotalVirtual;
  public ulong ullAvailVirtual;
  public ulong ullAvailExtendedVirtual;
}

Usage

var status = new MEMORYSTATUSEX();
GlobalMemoryStatusEx(status);