我使用System.Threading.Timer获得准确的三分钟间隔：
private System.Threading.Timer ReadTimer;
private System.Threading.TimerCallback ReadTimerCallback;
public Form1()
{
InitializeComponent();
}
#region Working with RichTextBox and system event log for logging
public enum LogStyle
{
InformationStyle = 0,
WarningStyle = 1,
ErrorStyle = 3
}
private delegate void LogTextDelegate(LogStyle logStyle, string message);
private int NewLinesCount(string Message)
{
string[] strings = { Environment.NewLine };
return Message.Split(strings, StringSplitOptions.RemoveEmptyEntries).Count();
}
private void AddText(LogStyle logStyle, string message)
{
LogBox.Select(0, 0);
string TextToAppend = DateTime.Now.ToString("dd.MM.yyyy HH:mm:ss.fff") + " " + message + Environment.NewLine;
LogBox.AppendText(TextToAppend);
LogBox.Select(LogBox.TextLength - TextToAppend.Length + NewLinesCount(TextToAppend), TextToAppend.Length);
switch (logStyle)
{
case LogStyle.InformationStyle:
{
EventLog.WriteEntry(Process.GetCurrentProcess().ProcessName, TextToAppend, EventLogEntryType.Information);
LogBox.SelectionColor = Color.Green;
LogBox.Select(LogBox.TextLength, LogBox.TextLength);
break;
}
case LogStyle.WarningStyle:
{
EventLog.WriteEntry(Process.GetCurrentProcess().ProcessName, TextToAppend, EventLogEntryType.Warning);
LogBox.SelectionColor = Color.DarkOrange;
LogBox.Select(LogBox.TextLength, LogBox.TextLength);
break;
}
case LogStyle.ErrorStyle:
{
EventLog.WriteEntry(Process.GetCurrentProcess().ProcessName, TextToAppend, EventLogEntryType.Error);
LogBox.SelectionColor = Color.Red;
LogBox.Select(LogBox.TextLength, LogBox.TextLength);
break;
}
}
}
public void LogText(LogStyle logStyle, string Message)
{
if (LogBox.InvokeRequired)
{
LogBox.Invoke(new LogTextDelegate(this.AddText), new object[] { logStyle, Message });
}
else
{
AddText(logStyle, Message);
}
}
#endregion
private void button1_Click(object sender, EventArgs e)
{
LogText(LogStyle.WarningStyle, "Current thread ID = " + System.Threading.Thread.CurrentThread.ManagedThreadId);
LogText(LogStyle.WarningStyle, "Threads count = " + System.Diagnostics.Process.GetCurrentProcess().Threads.Count);
AutoResetEvent ReadautoEvent = new AutoResetEvent(false);
ReadTimerCallback = new TimerCallback(this.ShowText);
ReadTimer = new System.Threading.Timer(ReadTimerCallback, ReadautoEvent, (long)(CurrentTime.AddMinutes(3) - DateTime.Now).TotalMilliseconds, 180000);
}
public void ShowText(object Object)
{
ReadTimer.Change((long)(CurrentTime.AddMinutes(3) - DateTime.Now).TotalMilliseconds, 180000);
LogText(LogStyle.WarningStyle, "Now is " + DateTime.Now.ToString("dd.MM.yyyy HH:mm:ss.fff"));
LogText(LogStyle.WarningStyle, "Now is " + "Current thread ID = " + System.Threading.Thread.CurrentThread.ManagedThreadId);
LogText(LogStyle.WarningStyle, "Threads count = " + System.Diagnostics.Process.GetCurrentProcess().Threads.Count);
}
private DateTime CurrentTime
{
get
{
DateTime now = DateTime.Now;
DateTime val;
val = new DateTime(now.Year, now.Month, now.Day, now.Hour, now.Minute, 0)
.AddMinutes(((now.Minute) / 3) * 3 - now.Minute);
return val;
}
}
但有时我会看到以下内容：
14.03.2012 09:20:33.264 Current thread ID = 10
14.03.2012 09:20:33.361 Threads count = 13
14.03.2012 09:20:59.985 Now is 14.03.2012 09:20:59.977
14.03.2012 09:20:59.991 Now is Current thread ID = 12
14.03.2012 09:20:59.997 Threads count = 15
14.03.2012 09:21:00.010 Now is 14.03.2012 09:21:00.009
14.03.2012 09:21:00.019 Now is Current thread ID = 12
14.03.2012 09:21:00.025 Threads count = 17
14.03.2012 09:24:00.252 Now is 14.03.2012 09:24:00.252
14.03.2012 09:24:00.260 Now is Current thread ID = 8
14.03.2012 09:24:00.268 Threads count = 17
14.03.2012 09:27:00.331 Now is 14.03.2012 09:27:00.330
14.03.2012 09:27:00.337 Now is Current thread ID = 6
14.03.2012 09:27:00.343 Threads count = 14
14.03.2012 09:30:00.021 Now is 14.03.2012 09:30:00.021
14.03.2012 09:30:00.027 Now is Current thread ID = 8
14.03.2012 09:30:00.033 Threads count = 13
14.03.2012 09:32:59.962 Now is 14.03.2012 09:32:59.961
14.03.2012 09:32:59.968 Now is Current thread ID = 6
14.03.2012 09:32:59.974 Threads count = 13
14.03.2012 09:33:00.013 Now is 14.03.2012 09:33:00.013
14.03.2012 09:33:00.020 Now is Current thread ID = 6
14.03.2012 09:33:00.026 Threads count = 14
14.03.2012 09:35:59.891 Now is 14.03.2012 09:35:59.891
14.03.2012 09:35:59.898 Now is Current thread ID = 8
14.03.2012 09:35:59.904 Threads count = 13
14.03.2012 09:36:00.001 Now is 14.03.2012 09:35:59.999
14.03.2012 09:36:00.008 Now is 14.03.2012 09:36:00.004
14.03.2012 09:36:00.015 Now is Current thread ID = 8
14.03.2012 09:36:00.021 Now is Current thread ID = 6
14.03.2012 09:36:00.030 Threads count = 14
14.03.2012 09:36:00.035 Threads count = 14
为什么这会在三分钟的时间间隔内执行两次：14.03.2012 09：20：59.985和14.03.2012 09：21：00.010？
我必须解决这个问题？
在CurrentTime我必须添加30秒
DateTime now = DateTime.Now.AddSeconds(30)还是什么？
答案 0 :(得分：2)
这里有一些问题。我看到的最大的是CurrentTime属性：
DateTime now = DateTime.Now;
DateTime val;
val = new DateTime(now.Year, now.Month, now.Day, now.Hour, now.Minute, 0)
.AddMinutes(((now.Minute) / 3) * 3 - now.Minute);
return val;
考虑当now.Minute为59，59/3 = 19时会发生什么，因为这是一个int。表达式59/3 * 3 - 59的其余部分会生成-2。你有效地将计时器倒回两分钟。 但是，因为您将创建val的秒数归零，所以您确实将计时器设置为3分钟。 59不是一个独特的案例，但我从你的数据点集中提取它。使用CurrentTime的代码会增加3分钟。所以你几乎要告诉代码立即解雇。你看到它被提升两次的原因是因为ShowText中的这一行：
`ReadTimer.Change((long)(CurrentTime.AddMinutes(3) - DateTime.Now).TotalMilliseconds, 180000);`
当您的委托处理计时器时，事件会立即再次引发，因为now.Minute仍为59，导致您的整体CurrentTime计算比DateTime.Now小3分钟。< / p>
如果您想要做的就是每三分钟运行一次任务，那么您只需要以下内容：
ReadTimer = new System.Threading.Timer(ReadTimerCallback, ReadautoEvent, 0, 180000);