[C#] WinAPI(Kernel32 dll) 사용하기

Kernel32.dll에서 GetSystemTime / SetSystemTime 호출해서 사용하기

 

C# / .NET 에서 Native DLL (Unmanaged DLL)에 있는 함수를 호출하는 P/Inovoke(Platform Invoke) 방식을 사용하여

C#에서 WinAPI를 호출하거나 C/C++로 작성된 Native DLL 함수를 호출한다.

    

 

 

1. DllImport 키워드를 사용해서 함수 호출하기

using System.Runtime.InteropServices; 

namespace TEST.APIs
{
    public static class Kernel32
    {
        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool GetSystemTime(ref SYSTEMTIME st);

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool SetSystemTime(ref SYSTEMTIME st);
    }
}

 

2. Struct SYSTEMTIME

using System.Runtime.InteropServices;

namespace TEST.APIs
{
    [StructLayout(LayoutKind.Sequential)]
    public struct SYSTEMTIME
    {
        public short Year;
        public short Month;
        public short DayOfWeek;
        public short Day;
        public short Hour;
        public short Minute;
        public short Second;
        public short Milliseconds;
    }

3. 호출해서 사용하기

//GetSystemTime
SYSTEMTIME getDate = new SYSTEMTIME();
GetSystemTime(ref getDate);
Console.Write("getSystemtime year: {0}", getDate.Year);


//SetSystemTime
public void SetSystemTimeFromDbServer()
{
    using (var db = MasterContext.CreateDatabase())
    {
        var dbDate = db.ScalarQuery("SELECT GETDATE()").ExToDateTime(DateTime.Now).ToUniversalTime();
        //
        //
        //
        APIs.SYSTEMTIME setDate = new APIs.SYSTEMTIME();
        setDate.Year   = (short)dbDate.Year;
        setDate.Month  = (short)dbDate.Month;
        setDate.Day    = (short)dbDate.Day;
        setDate.Hour   = (short)dbDate.Hour;
        setDate.Minute = (short)dbDate.Minute;
        setDate.Second = (short)dbDate.Second;
        //
        //
        //
        APIs.Kernel32.SetSystemTime(ref setDate);
    }
}