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如何在C#中創(chuàng)建一個(gè)高精度的定時(shí)器?相信很多沒有經(jīng)驗(yàn)的人對此束手無策,為此本文總結(jié)了問題出現(xiàn)的原因和解決方法,通過這篇文章希望你能解決這個(gè)問題。
System.Threading.Timer
System.Timers.Timer
System.Windows.Forms.Timer (Windows Forms 的定時(shí)器)
System.Windows.Threading.DispatcherTimer (WPF 的定時(shí)器)
通常他們的精度只能維持在10-20ms之間,這個(gè)和操作系統(tǒng)相關(guān),所以我們在很多場景下面這個(gè)是不能夠達(dá)到我們精度的要求的,如果要實(shí)現(xiàn)這一需求我們該怎么辦,當(dāng)然也有很多辦法,今天主要介紹一種Stopwatch來實(shí)現(xiàn)的方式,網(wǎng)上有很多采用Win32 Dll的API這個(gè)當(dāng)然是可以的,這篇文章的重點(diǎn)不是去討論這個(gè),關(guān)于使用Win32 API的方式可以參考這里。
using System; using System.Collections.Generic; using System.Diagnostics; using System.Linq; using System.Runtime.InteropServices; using System.Text; namespace Pangea.Common.Utility { /// <summary> /// .Net Stopwatch對高精度定時(shí)器作了很好的包裝 /// DeviceTimer內(nèi)部采用Stopwatch類實(shí)現(xiàn)高精度定時(shí)操作 /// </summary> public sealed class DeviceTimer { #if USE_CPU_COUNTING //引入高性能計(jì)數(shù)器API,通過對CPU計(jì)數(shù)完成計(jì)時(shí) [DllImport("Kernel32.dll")] private static extern bool QueryPerformanceCounter(out long lpPerformanceCount); //獲取當(dāng)前CPU的工作頻率 [DllImport("Kernel32.dll")] private static extern bool QueryPerformanceFrequency(out long lpFrequency); #else /// <summary> /// 獲取TickCount64計(jì)數(shù) /// </summary> /// <returns></returns> //[DllImport("kernel32.dll")] //public static extern long GetTickCount64(); #endif private enum DeviceTimerState { TM_ST_IDLE = 0, TM_ST_BUSY = 1, TM_ST_TIMEOUT = 2, } /// <summary> /// Stopwatch object /// </summary> Stopwatch _stopWatch = new Stopwatch(); /// <summary> /// 定時(shí)器內(nèi)部狀態(tài) /// </summary> DeviceTimerState _state; /// <summary> /// 定時(shí)器開始計(jì)時(shí)時(shí)刻的相對時(shí)間點(diǎn) /// </summary> long _startTime; /// <summary> /// 定時(shí)器超時(shí)時(shí)刻的相對時(shí)間點(diǎn) /// </summary> long _timeOut; #if USE_CPU_COUNTING /// <summary> /// CPU運(yùn)行的時(shí)鐘頻率 /// </summary> double _freq; #endif /// <summary> /// 定時(shí)時(shí)間(單位:ms) /// </summary> double _duration; /// <summary> /// class constructure /// </summary> public DeviceTimer() { #if USE_CPU_COUNTING long freq; if (QueryPerformanceFrequency(out freq) == false) throw new Exception("本計(jì)算機(jī)不支持高性能計(jì)數(shù)器"); //得到每1ms的CPU計(jì)時(shí)TickCount數(shù)目 _freq = (double)freq / 1000.0; QueryPerformanceCounter(out _startTime); #else _stopWatch.Start(); _startTime = 0; #endif SetState(DeviceTimerState.TM_ST_IDLE); _timeOut = _startTime; _duration = 0; } /// <summary> /// 內(nèi)部調(diào)用:設(shè)置定時(shí)器當(dāng)前狀態(tài) /// </summary> /// <param name="state"></param> private void SetState(DeviceTimerState state) { _state = state; } /// <summary> /// 內(nèi)部調(diào)用:返回定時(shí)器當(dāng)前狀態(tài) /// </summary> /// <returns></returns> private DeviceTimerState GetState() { return _state; } /// <summary> /// 定時(shí)器開始計(jì)時(shí)到現(xiàn)在已流逝的時(shí)間(單位:毫秒) /// </summary> /// <returns></returns> public double GetElapseTime() { long curCount; #if USE_CPU_COUNTING QueryPerformanceCounter(out curCount); return (double)(curCount - _startTime) / (double)_freq; #else curCount = _stopWatch.ElapsedMilliseconds; return curCount - _startTime; #endif } /// <summary> /// 獲取定時(shí)總時(shí)間 /// </summary> /// <returns></returns> public double GetTotalTime() { return _duration; } /// <summary> /// 停止計(jì)時(shí)器計(jì)時(shí) /// </summary> public void Stop() { SetState(DeviceTimerState.TM_ST_IDLE); #if USE_CPU_COUNTING QueryPerformanceCounter(out _startTime); #else _startTime = _stopWatch.ElapsedMilliseconds; #endif _timeOut = _startTime; _duration = 0; } /// <summary> /// 啟動(dòng)定時(shí)器 /// </summary> /// <param name="delay_ms">定時(shí)時(shí)間(單位:毫秒)</param> public void Start(double delay_ms) { #if USE_CPU_COUNTING QueryPerformanceCounter(out _startTime); _timeOut = Convert.ToInt64(_startTime + delay_ms * _freq); #else _startTime = _stopWatch.ElapsedMilliseconds; _timeOut = Convert.ToInt64(_startTime + delay_ms); #endif SetState(DeviceTimerState.TM_ST_BUSY); _duration = delay_ms; } /// <summary> /// 重新開始定時(shí)器 /// 開始的計(jì)時(shí)時(shí)間以上一次Start的時(shí)間為準(zhǔn) /// </summary> /// <param name="delay_ms">定時(shí)時(shí)間(單位:毫秒)</param> public void Restart(double delay_ms) { #if USE_CPU_COUNTING _timeOut = Convert.ToInt64(_startTime + delay_ms * _freq); #else _timeOut = Convert.ToInt64(_startTime + delay_ms); #endif SetState(DeviceTimerState.TM_ST_BUSY); _duration = delay_ms; } /// <summary> /// 返回定時(shí)器是否超時(shí) /// </summary> /// <returns></returns> public bool IsTimeout() { if (_state == DeviceTimerState.TM_ST_IDLE) { //System.Diagnostics.Debug.WriteLine("Warning: Misuage of the device timer. You must start it first before you can use it."); //System.Diagnostics.Debug.Assert(false, "Warning: Misuage of the device timer. You must start it first before you can use it."); } long curCount; #if USE_CPU_COUNTING QueryPerformanceCounter(out curCount); #else curCount = _stopWatch.ElapsedMilliseconds; #endif if (_state == DeviceTimerState.TM_ST_BUSY && (curCount >= _timeOut)) { SetState(DeviceTimerState.TM_ST_TIMEOUT); return true; } else if (_state == DeviceTimerState.TM_ST_TIMEOUT) { return true; } return false; } /// <summary> /// 定時(shí)器是否在工作中 /// </summary> /// <returns></returns> public bool IsIdle() { return (_state == DeviceTimerState.TM_ST_IDLE); } } }
這個(gè)里面我們在DeviceTimer中定義了一個(gè)私有的_stopWatch 對象并且在構(gòu)造函數(shù)中就啟動(dòng)了這個(gè)Stopwatch,所以我們在使用的時(shí)候是通過先創(chuàng)建一個(gè)DeveiceTimer的對象然后我們再調(diào)用內(nèi)部的Start方法,當(dāng)然在調(diào)用這個(gè)方法的時(shí)候我們需要傳入一個(gè)定時(shí)時(shí)間,然后不斷檢測IsTimeout方法看是否到達(dá)定時(shí)時(shí)間,從而達(dá)到類似于定時(shí)時(shí)間到的效果,另外GetElapseTime()方法能夠獲取從調(diào)用Start方法開始到現(xiàn)在的時(shí)間,另外我們還在其中定義了幾個(gè)枚舉值用來表示當(dāng)前DeviceTimer的狀態(tài)用于做一些狀態(tài)的校驗(yàn),具體數(shù)值如下。
private enum DeviceTimerState { TM_ST_IDLE = 0, TM_ST_BUSY = 1, TM_ST_TIMEOUT = 2, }
這里還有最后一個(gè)問題就是循環(huán)調(diào)用的問題,這個(gè)其實(shí)也是非常簡單就在一個(gè)While循環(huán)中不斷進(jìn)行調(diào)用,當(dāng)然下面的代碼可以有很多內(nèi)容供我們?nèi)グl(fā)揮的,這個(gè)可以根據(jù)自己的需要進(jìn)行修改。
using System; using System.Threading.Tasks; namespace DeviceTimerConsoleApp { class Program { private static bool flag = true; static void Main(string[] args) { Task.Factory.StartNew(() => { var deviceTimer = new DeviceTimer(); deviceTimer.Start(5); while (flag) { if (deviceTimer.IsTimeout()) { Console.WriteLine($"定時(shí)時(shí)間已到,距離開始執(zhí)行已過去:{deviceTimer.GetElapseTime()}ms"); deviceTimer.Start(5); } } }); Console.ReadKey(); } } }
看完上述內(nèi)容,你們掌握如何在C#中創(chuàng)建一個(gè)高精度的定時(shí)器的方法了嗎?如果還想學(xué)到更多技能或想了解更多相關(guān)內(nèi)容,歡迎關(guān)注億速云行業(yè)資訊頻道,感謝各位的閱讀!
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