GetLastWriteTime returning 12/31/1600 7:00:00 PM

问题:

I am using the following code to write the Date Modified time of a Directory to a label

string selectedPath = comboBox1.SelectedItem.ToString();
DateTime lastdate = Directory.GetLastWriteTime(selectedPath);
datemodified.Text = lastdate.ToString();

It returns the date 12/31/1600 7:00:00 PM which I have no clue where it is getting that date from. Can anyone help me understand why it is returning that date and how I can fix it? I'm using .NET 3.5

回答1:

From the documentation:

If the directory described in the path parameter does not exist, this method returns 12:00 midnight, January 1, 1601 A.D. (C.E.) Coordinated Universal Time (UTC), adjusted to local time.

So presumably your time zone is UTC-5 (in January), and the directory doesn't exist...

回答2:

first thought is that of is your time set correctly. Second thought is to right click on that folder and see what it says in properties. Lastly I'd make new test folder and run that bit of GetLastWriteTime tests on it so you know what you are getting back.

回答3:

GetLastWriteTime not always return reliable date time, use this

string selectedPath = comboBox1.SelectedItem.ToString();
DateTime now = DateTime.Now;
TimeSpan localOffset = now - now.ToUniversalTime();
DateTime lastdate = File.GetLastWriteTimeUtc(selectedPath) + localOffset;
datemodified.Text = lastdate.ToString();

回答4:

Old question, but today I faced this issue. That particular date is also returned when your path is invalid or the file doesn't exists, because there is no built in exception in any of those cases.