我想创建一个计时器,它在特定时间每 24 小时调用一个方法。我不想通过 Windows Scheduler 执行此操作,而是应该在代码中完成。这是我目前使用的代码:
DateTime now = DateTime.Now;
DateTime today = now.Date.AddHours(16);
DateTime next = now <= today ? today : today.addDays(1);
Systems.Threading.TimerCallback callback = new TimerCallback(DisplayMessage);
Systems.Threading.Timer timer = new System.Threading.Timer(callback, null, next - now, TimeSpan.FromHours(24));
我的问题是,如果 next
最终距离当前时间只有几分钟,那么代码会工作并通过 DisplayMessage()
显示消息。如果时差大于几分钟,代码将无法运行,不会出现异常、崩溃或任何情况。我已经尝试在 DisplayMessage()
中放置日志语句、消息框和断点,以确保我能够正确地看到何时调用了 DisplayMessage()
,但是没有运气。
最佳答案
这是一个工作示例。
public class Scheduler {
private readonly List<Task> _Tasks;
private Timer _Timer;
public Scheduler() {
_Tasks = new List<Task>();
}
public void ScheduleTask(Task task) {
_Tasks.Add(task);
}
public void CancelTask(Task task) {
_Tasks.Remove(task);
}
//Start the timer.
public void Start() {
//Set the interval based on what amount of accurcy you need.
_Timer = new Timer {
Interval = 1000
};
_Timer.Elapsed += (sender, args) => UpdateTasks();
_Timer.Enabled = true;
}
//Check to see if any task need to be executed.
private void UpdateTasks() {
for (int i = 0; i < _Tasks.Count; i++) {
Task task = _Tasks[i];
if (task.ExecuteTime >= DateTime.Now) {
task.Callback();
_Tasks.Remove(task);
}
_Tasks.Remove(task);
}
}
//Stop the timer when you are done.
public void Stop() {
_Timer.Dispose();
}
}
//Use this to schedule a task.
public class Task {
public DateTime ExecuteTime { get; set; }
public Action Callback { get; set; }
public Task(DateTime executeTime, Action callback) {
ExecuteTime = executeTime;
Callback = callback;
}
}
关于c# - 每 24 小时定时一次,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18794435/