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C#定点任务代码 类似Windows计划任务（健壮性高） - 更多技术 - 清泛网 - ...
...间隔
SetNextOnceDoInterval();
if (DateTime.Now.ToString("HH:mm").CompareTo(onceDoStr.Trim()) >= 0)
{
// 可能由于系统原因导致触发过早的，不执行
onceDoMain();
}
}
/// <summa...
Postgresql - unable to drop database because of some auto connections to DB
...tever was trying to auto-connect should no longer be able to do so.
You'll now be able to drop the DB.
This won't work if you're using superuser connections for normal operations, but if you're doing that you need to fix that problem first.
After you're done dropping the database, if you create the...
Surrogate vs. natural/business keys [closed]
...
Now, after reading a lot about surrogate keys and natural keys, I think using surrogate keys is better. But, on my database, natural keys (a NVARCHAR(20)) must be unique. I don't understand how I can get more speed if I need ...
How to select a CRAN mirror in R
...rg"
options(repos=r)
})
which is in ~/.Rprofile.
Edit: As it is now 2018, we can add that for the last few years the URL "https://cloud.r-project.org" has been preferable as it reflects a) https access and b) an "always-near-you" CDN.
...
How to use arguments from previous command?
I know that Esc + . gives you the last argument of the last command.
11 Answers
11...
Optional query string parameters in ASP.NET Web API
...
This issue has been fixed in the regular release of MVC4.
Now you can do:
public string GetFindBooks(string author="", string title="", string isbn="", string somethingelse="", DateTime? date= null)
{
// ...
}
and everything will work out of the box.
...
How to “properly” create a custom object in JavaScript?
...ype.toString= function() {
return 'Shape at '+this.x+', '+this.y;
};
Now to subclass it, in as much as you can call what JavaScript does subclassing. We do that by completely replacing that weird magic prototype property:
function Circle(x, y, r) {
Shape.call(this, x, y); // invoke the ba...
Confusion between factor levels and factor labels
...seems to be a difference between levels and labels of a factor in R.
Up to now, I always thought that levels were the 'real' name of factor levels, and labels were the names used for output (such as tables and plots). Obviously, this is not the case, as the following example shows:
...
How do I time a method's execution in Java?
...ited Jul 8 '16 at 21:49
michaelsnowden
5,33022 gold badges2727 silver badges6767 bronze badges
answered Oct 7 '08 at 20:16
...
Why are Subjects not recommended in .NET Reactive Extensions?
...ppropriate FromEvent method and we are done. To the Pub!
For option 2, we now need to consider how we poll this and how to do this effciently. Also when we get the value, how do we publish it?
I would imagine that you would want a dedicated thread for polling. You wouldn't want some other coder ha...