C#游戏开发中精确的时间调配

方法一：参考《精通C#游戏编程》一书。根据学习WorldWind源码可知，WorldWind中采用的方法与该方法基本一致。

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.InteropServices;



namespace GameLoop//根据需要修改名称空间

{

    public class PreciseTimer

    {

        [System.Security.SuppressUnmanagedCodeSecurity]

        [DllImport("kernel32")]

        private static extern bool QueryPerformanceFrequency(ref long PerformanceFrequency);



        [System.Security.SuppressUnmanagedCodeSecurity]

        [DllImport("kernel32")]

        private static extern bool QueryPerformanceCounter(ref long PerformanceCount);



        long _ticksPerSecond = 0;

        long _previousElapsedTime = 0;



        public PreciseTimer()

        {

            QueryPerformanceFrequency(ref _ticksPerSecond);

            GetElapsedTime(); // Get rid of first rubbish result

        }



        public double GetElapsedTime()

        {

            long time = 0;

            QueryPerformanceCounter(ref time);



            double elapsedTime = (double)(time - _previousElapsedTime) / (double)_ticksPerSecond;

            _previousElapsedTime = time;



            return elapsedTime;

        }

    }

}