前言：想在.net framework环境使用自定义定时器的话，参考我的另一篇文章：https://www.cnblogs.com/lxhbky/p/10242839.html
想在.net core中使用定时器功能，需要借助一个服务接口：IHostedService, 继承并实现对应方法，最后再setup.cs类中添加注册服务：services.AddHostedService<实现服务类>(); 既然要写计时器的服务器，那么该实现类就要包含定时器，本篇博客也是借助System.Timers.Timer类封装的。
下面展示具体代码：
1-公用基类：
public class ModelBase
{
protected IServiceProvider Services { get; set; }
protected IWebHostEnvironment WebHostEnvironment { get; set; }
/// <summary>
/// 配置帮助类
/// </summary>
protected ConfigHelper ConfigHelper { get; set; }
/// <summary>
/// 等同于ASP.NET里面的WebCache(HttpRuntime.Cache)
/// </summary>
protected IMemoryCache MemoryCache { get; set; } /// <summary>
/// 日志
/// </summary>
protected ILogger Logger { get; set; } /// <summary>
/// 授权帮助
/// </summary>
protected OAuthHelper OAuthHelper { get; set; } /// <summary>
/// HttpClient帮助工厂
/// </summary>
protected IHttpClientFactory HttpClientFactory { get; set; } public ModelBase(params object[] @params)
{
foreach (var item in @params)
{
if (item is IServiceProvider)
{
this.Services = (IServiceProvider)item;
}
else if (item is IWebHostEnvironment)
{
this.WebHostEnvironment = (IWebHostEnvironment)item;
}
else if (item is ConfigHelper)
{
this.ConfigHelper = (ConfigHelper)item;
}
else if (item is IMemoryCache)
{
this.MemoryCache = (IMemoryCache)item;
}
else if (item is ILogger)
{
this.Logger = (ILogger)item;
}
else if (item is OAuthHelper)
{
this.OAuthHelper = (OAuthHelper)item;
}
else if (item is IHttpClientFactory)
{
this.HttpClientFactory = (IHttpClientFactory)item;
} } }
}
2-计时器封装类：
相对于.net framework文章计时器部分的类做了对应优化，更加简化了：
using Microsoft.Extensions.Logging;
using PaymentAccountAPI.Common;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Timers; namespace PaymentAccountAPI.Helper
{
/// <summary>
/// 定时周期帮助类
/// </summary>
public class TimeCycleHelp : ModelBase
{
public TimeCycleHelp(ILogger<TimeCycleHelp> logger) : base(logger)
{
this.Timer = new System.Timers.Timer();
} /// <summary>
/// 服务专属计时器
/// </summary>
private System.Timers.Timer Timer; /// <summary>
/// 默认计时器时间间隔1秒（提高计时器开始时间准确度）
/// </summary>
private double DefaultTimerInterval = * ; /// <summary>
/// 设置多个循环周期
/// </summary>
private List<TimeCycle> TimeCycleList { get; set; } /// <summary>
/// 更新一个计时器的计时周期
/// </summary>
/// <param name="newTimerInterval">新的计时周期</param>
/// <param name="isFirstStart">是否是首次更新计时器周期</param>
private void UpdateTimeInterval(double newTimerInterval, bool isFirstStart = false)
{
if (this.Timer != null && newTimerInterval > )
{
this.Timer.Stop();
if (this.Timer.Interval != newTimerInterval)
{
this.Timer.Interval = newTimerInterval;
}
if (isFirstStart)
{
this.Timer.Elapsed += new System.Timers.ElapsedEventHandler(this.ServiceAction);
}
this.Timer.AutoReset = true;
this.Timer.Start();
}
} /// <summary>
/// 内部辅助方法
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ServiceAction(object sender, ElapsedEventArgs e)
{
List<TimeCycle> currentTimeCycleList = new List<TimeCycle>(); DateTime now = DateTime.Now;
DateTime cycleBeginTime;
DateTime cycleEndTime;
foreach (TimeCycle timeCycle in this.TimeCycleList)
{
cycleBeginTime = Convert.ToDateTime(timeCycle.BeginTime);
cycleBeginTime = now.Date.AddHours(cycleBeginTime.Hour).AddMinutes(cycleBeginTime.Minute).AddSeconds(cycleBeginTime.Second);
cycleEndTime = Convert.ToDateTime(timeCycle.EndTime);
cycleEndTime = now.Date.AddHours(cycleEndTime.Hour).AddMinutes(cycleEndTime.Minute).AddSeconds(cycleEndTime.Second);
if (cycleEndTime < cycleBeginTime)
{
cycleEndTime = cycleEndTime.AddDays();
} if (now >= cycleBeginTime && now <= cycleEndTime)
{
//有最大执行次数限制或者没有限制
if (timeCycle.ActionExecutionTimes < timeCycle.MaxActionTimes || timeCycle.MaxActionTimes == )
{
TimeSpan timeSpan = now - cycleBeginTime;
bool isCanAction = (int)timeSpan.TotalSeconds % timeCycle.ActionSeconds == ? true : false;
if (isCanAction)
{
timeCycle.ActionExecutionTimes++;
currentTimeCycleList.Add(timeCycle);
}
}
}
else
{
//不在计时周期内，已执行次数清零
timeCycle.ActionExecutionTimes = ;
}
}
//找到当前循环周期后，执行周期内动作
if (currentTimeCycleList.Count > )
{
currentTimeCycleList.ForEach(item =>
{
//使用多线程执行任务，让代码快速执行
Task.Run(() => item.Action());
});
}
} /// <summary>
/// 开启计时器
/// </summary>
/// <param name="timeCycleArray"></param>
public void Start(params TimeCycle[] timeCycleArray)
{
if (timeCycleArray != null && timeCycleArray.Length > )
{
if (this.TimeCycleList == null)
{
this.TimeCycleList = new List<TimeCycle>();
}
this.TimeCycleList = timeCycleArray.ToList(); //设置首次计时器周期（首次动作执行，是在计时器启动后在设置的时间间隔后做出的动作）
this.UpdateTimeInterval(this.DefaultTimerInterval, true);
}
} /// <summary>
/// 结束计时器
/// </summary>
public void Stop()
{
this.Timer.Stop();
} } /// <summary>
/// 计时周期类
/// </summary>
public class TimeCycle
{
/// <summary>
/// 唯一标识
/// </summary>
public int ID { get; set; }
/// <summary>
/// 开始时间(误差1秒=取决于计时器默认时间间隔)
/// </summary>
public string BeginTime { get; set; }
/// <summary>
/// 结束时间
/// </summary>
public string EndTime { get; set; }
/// <summary>
/// 最大执行次数
/// </summary>
public int MaxActionTimes { get; set; }
/// <summary>
/// 计时周期内执行的动作(动作会在到达开始时间后的)
/// </summary>
public Action Action { get; set; }
/// <summary>
/// 动作执行时间间隔（秒）
/// </summary>
public int ActionSeconds { get; set; }
/// <summary>
/// 方法执行次数
/// </summary>
internal int ActionExecutionTimes { get; set; } public TimeCycle(int id, Action action, int actionSeconds) : this(id, "00:00:00", action, actionSeconds)
{
} public TimeCycle(int id, string beginTime, Action action, int actionSeconds) : this(id, beginTime, action, actionSeconds, )
{
} public TimeCycle(int id, string beginTime, Action action, int actionSeconds, int maxActionTimes) : this(id, beginTime, "23:59:59", action, actionSeconds, maxActionTimes)
{
} /// <summary>
/// 基本构造器
/// </summary>
/// <param name="id">唯一标识</param>
/// <param name="beginTime">开始时间</param>
/// <param name="endTime">结束时间</param>
/// <param name="action">要执行的任务</param>
/// <param name="actionSeconds">任务执行时间间隔</param>
/// <param name="maxActionTimes">最大执行次数</param>
public TimeCycle(int id, string beginTime, string endTime, Action action, int actionSeconds, int maxActionTimes)
{
this.ID = id;
this.BeginTime = beginTime;
this.EndTime = endTime;
this.Action = action;
this.ActionSeconds = actionSeconds;
this.MaxActionTimes = maxActionTimes;
}
}
}
3-webAPI服务封装类：
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using PaymentAccountAPI.Common;
using PaymentAccountAPI.Helper;
using PaymentAccountAPI.PaymentAccountHelper;
using System;
using System.Threading;
using System.Threading.Tasks; namespace PaymentAccountAPI.Hangfire
{
public class SyncToCMSService : ModelBase, IHostedService
{private TimeCycleHelp _TimeCycleHelp { get; set; } public SyncToCMSService(ConfigHelper configHelper,
TimeCycleHelp timeCycleHelp, ILogger<SyncToCMSService> logger) : base(logger, configHelper)
{this._TimeCycleHelp = timeCycleHelp;
} public void SyncData()
{
//...需要执行的任务代码 this.Logger.LogInformation($"定时任务：完成{currentDate.ToShortDateString()}的交易记录同步！");
} public Task StartAsync(CancellationToken cancellationToken)
{
this.Logger.LogInformation($"定时任务：同步服务已启动..."); //正式代码
string syncBeginTime = this.ConfigHelper.GetAppSettingValue("SyncCMSBeginTime");
string syncEndTime = this.ConfigHelper.GetAppSettingValue("SyncCMSEndTime");
this._TimeCycleHelp.Start(new TimeCycle(, syncBeginTime, syncEndTime, this.SyncData, , )); //测试代码
//this._TimeCycleHelp.Start(new TimeCycle(999, "12:00:00", () =>
//{
// this.Logger.LogInformation("test123");
//}, 10, 3)); return Task.CompletedTask;
} public Task StopAsync(CancellationToken cancellationToken)
{
this.Logger.LogInformation($"同步服务已停止...");
this._TimeCycleHelp.Stop(); return Task.CompletedTask;
} }
}
4-在startup.cs添加注册服务：
#region 添加定时任务
services.AddSingleton<TimeCycleHelp>();
services.AddHostedService<SyncToCMSService>();
#endregion
5-部署到IIS站点项目时的注意事项（引用下面道友的一段话）：
关于GenericHost的生存周期问题
如果你使用的是控制台启动，则此问题暂时可以忽略。
如果你使用的是站点项目，并且还是通过IIS启动，那么你可能要注意了，因为.net core 的站点自身是有HOST宿主处理，IIS是其上代理，其启动关闭，端口映射等由IIS内部完成。所以其依然受限于IIS的闲置回收影响，当IIS闲置回收时，其后的.Net Host也会被一同关闭，需要有新的请求进来时才会再次启动。不过鉴于当前任务处理已经如此简单，有个取巧的做法，实现一个站点自身的心跳检测任务，IIS默认20分钟回收，任务时间可以设为15分钟（你也可以设置IIS站点回收时间），当然如果你的任务如果没有那么严格的时间要求你也可以不用处理，因为回收后一旦接受到新的请求，任务会再次发起。
最后感谢一篇道友的文章：.Net Core 简单定时任务框架封装
