如何在C#中声明LARGE_INTEGER

using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Sequential)]
public struct LARGE_INTEGER
{
    public long QuadPart;
}

LARGE_INTEGER li = new LARGE_INTEGER();

using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Sequential)]
public struct LARGE_INTEGER
{
    public long QuadPart;
}

public class Program
{
    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern void GetSystemTimePreciseAsFileTime(out LARGE_INTEGER lpSystemTimeAsFileTime);

    public static void Main()
    {
        LARGE_INTEGER li = new LARGE_INTEGER();
        GetSystemTimePreciseAsFileTime(out li);
        Console.WriteLine("Current time in ticks: {0}", li.QuadPart);
    }
}