dxtimer.cs

这是网上下载的很好的串口发短信的程序! 是用VC++来做的

using System;
using System.Runtime.InteropServices;
using System.Security;

namespace DDGameHelper
{
	#region Timer 用到的命令参数枚举
	/// <summary>
	/// Enumeration for various actions our timer can perform
	/// </summary>
	public enum TimerCmd
	{
		/// <summary>
		/// 复位
		/// </summary>
		Reset, 
		/// <summary>
		/// 开始
		/// </summary>
		Start, 
		/// <summary>
		/// 暂停
		/// </summary>
		Stop, 
		/// <summary>
		/// 令 Stop Time 增加 0.1 秒
		/// </summary>
		Advance,
		/// <summary>
		/// 获取自游戏运行以来到现在经过的绝对时间
		/// </summary>
		GetAbsoluteTime, 
		/// <summary>
		/// 获取自系统运行以来到现在经过的绝对时间
		/// </summary>
		GetApplicationTime, 
		/// <summary>
		/// 获取自上次调用以来经过的时间（微秒）
		/// </summary>
		GetElapsedTime 
	};
	#endregion

	/// <summary>
	/// DXTimer类（改自MS的示例代码）
	/// </summary>
	public class DXTimer
	{
		#region 私有成员定义
		[DllImport("kernel32"), SuppressUnmanagedCodeSecurity]
		private static extern bool QueryPerformanceFrequency(ref long PerformanceFrequency);

		[DllImport("kernel32"), SuppressUnmanagedCodeSecurity]
		private static extern bool QueryPerformanceCounter(ref long PerformanceCount);

		private bool isTimerInitialized = false;
		private bool m_bTimerStopped = true;
		private long m_llQPFTicksPerSec = 0;
		private long m_llStopTime = 0;
		private long m_llLastElapsedTime = 0;
		private long m_llBaseTime = 0;
		#endregion

		#region FPS 计算相关
		private int _frames=0;
		private double _lastTime=0.0f;
		private double _framePerSecond=0.0f;

		/// <summary>
		/// 计算并获取每秒帧速
		/// </summary>
		public double CalculateFPS()
		{
			double time = Timer(TimerCmd.GetAbsoluteTime);
			++_frames;

			// Update the scene stats once per second
			if (time - _lastTime > 1.0f)
			{
				_framePerSecond    = _frames / (time - _lastTime);
				_lastTime = time;
				_frames  = 0;
			}

			return _framePerSecond;
		}
		/// <summary>
		/// 每秒帧速
		/// </summary>
		public double FramePerSecond
		{
			get{return _framePerSecond;}
		}
		#endregion
		
		#region Timer相关
		/// <summary>
		/// 开始计时
		/// </summary>
		public void Start()
		{
			Timer(TimerCmd.Start);
		}

		/// <summary>
		/// 获取自上次调用以来，经过的毫秒数
		/// </summary>
		public double GetElapsedMillisecond()
		{
			return Timer(TimerCmd.GetElapsedTime)*1000.0;
		}

		/// <summary>
		/// 复位 timer
		/// </summary>
		public void Reset()
		{
			Timer(TimerCmd.Reset);
		}

		/// <summary>
		/// Performs timer opertations. Use the following commands:
		/// 
		///          TimerCmd.Reset - to reset the timer
		///          TimerCmd.Start - to start the timer
		///          TimerCmd.Stop - to stop (or pause) the timer
		///          TimerCmd.Advance - to advance the timer by 0.1 seconds
		///          TimerCmd.GetAbsoluteTime - to get the absolute system time
		///          TimerCmd.GetApplicationTime - to get the current time
		///          TimerCmd.GetElapsedTime - to get the time that elapsed between TIMER_GETELAPSEDTIME calls
		///
		/// </summary>
		public double Timer(TimerCmd command)
		{
			if (!isTimerInitialized)
			{
				isTimerInitialized = true;
				QueryPerformanceFrequency(ref m_llQPFTicksPerSec);
			}
			double time, fElapsedTime;
			long qwTime = 0;
		
			// Get either the current time or the stop time, depending
			// on whether we're stopped and what command was sent
			if (m_llStopTime != 0 && command != TimerCmd.Start && command != TimerCmd.GetAbsoluteTime)
				qwTime = m_llStopTime;
			else
				QueryPerformanceCounter(ref qwTime);

			// Return the elapsed time
			if (command == TimerCmd.GetElapsedTime)
			{
				fElapsedTime = (double) (qwTime - m_llLastElapsedTime) / (double) m_llQPFTicksPerSec;
				m_llLastElapsedTime = qwTime;
				return (double)fElapsedTime;
			}
	
			// Return the current time
			if (command == TimerCmd.GetApplicationTime)
			{
				double fAppTime = (double) (qwTime - m_llBaseTime) / (double) m_llQPFTicksPerSec;
				return (double)fAppTime;
			}
	
			// Reset the timer
			if (command == TimerCmd.Reset)
			{
				m_llBaseTime        = qwTime;
				m_llLastElapsedTime = qwTime;
				m_llStopTime        = 0;
				m_bTimerStopped     = false;
				return 0.0f;
			}
	
			// Start the timer
			if (command == TimerCmd.Start)
			{
				if (m_bTimerStopped)
					m_llBaseTime += qwTime - m_llStopTime;
				m_llStopTime = 0;
				m_llLastElapsedTime = qwTime;
				m_bTimerStopped = false;
				return 0.0f;
			}
	
			// Stop the timer
			if (command == TimerCmd.Stop)
			{
				if (!m_bTimerStopped)
				{
					m_llStopTime = qwTime;
					m_llLastElapsedTime = qwTime;
					m_bTimerStopped = true;
				}
				return 0.0f;
			}
	
			// Advance the timer by 1/10th second
			if (command == TimerCmd.Advance)
			{
				m_llStopTime += m_llQPFTicksPerSec/10;
				return 0.0f;
			}

			if (command == TimerCmd.GetAbsoluteTime)
			{
				time = qwTime / (double) m_llQPFTicksPerSec;
				return (double)time;
			}

			return -1.0f; // Invalid command specified
		}
		#endregion
	}
	
}