Comparing two FILETIME to see which is newer (CompareFileTime) [C# 2002]

[Shaitan00]

I have two FILETIME (using System.Runtime.InteropServices;) variables that contain File Times and I need to compare the two to find out who is never. In the

past (VC++6) I would simply use [-1 == CompareFileTime (&mrft, &ft)] but this doesn't seem to exist in C# [2002] nor am I able to find its replacement. So

how does one go about performing a CompareFileTime of two FileTime variables in C#?

FILETIME ft, ftMostRecent;
ftMostRecent.dwLowDateTime = 0;
ftMostRecent.dwHighDateTime = 0;

GetFileTime(&ft);
if (-1 == CompareFileTime (&ftMostRecent, &ft))
{
	// ... do something ... //
}

Specifically I need to know if "ft" is more recent then "ftMostRecent"...
Do I (and even can I) DLLImport the function itself (CompareFileTime)? If so how would the DllImport declaration go? And if not what else I can use or what other method can I utilize to get the same result?

Any help would be greatly appreciated.
Thanks,

[nemaroller]

System.IO.FileInfo class has a CreationTime property.

Edit:
Sorry, misinterpreted your post.

[Shaitan00]

Does System.IO.FileInfo have a replacement in C# for CompareFileTime?

[nemaroller]

The FileInfo.CreationTime property returns a full System.DateTime object so you can use the DateTime.Compare method.

In your case,. FileInfo.LastWriteTime property which is the modified time, or FileInfo.LastWriteTimeUtc (universal coordinate time) may be more appropriate.

http://msdn2.microsoft.com/en-us/library/5ata5aya.aspx

static void Main(string[] args)
		{
			DateTime t = DateTime.Now;
			System.Threading.Thread.Sleep(10);

			DateTime x = DateTime.Now;

			if (t > x) Console.WriteLine("That's not right.");
			else if (t < x)
				Console.WriteLine("That's better.");
			else 
				Console.WriteLine("They're equal.");

			Console.ReadLine();

		}

[nemaroller]

Of course, you can just compare the property values (note that UTC is good for comparing files on different machines or across networks, but may take a performance hit to convert the time to UTC - otherwise use LastWriteTime. You'll have to test that.):

static void Main(string[] args)
		{


			System.IO.FileInfo info1 = new System.IO.FileInfo(@"C:\testfile1.txt");
			System.IO.FileInfo info2 = new System.IO.FileInfo(@"C:\testfile2.txt");

			if (info1.LastWriteTimeUtc > info2.LastWriteTimeUtc)
				Console.WriteLine("testfile1 is newer.");
			else if (info1.LastWriteTimeUtc < info2.LastWriteTimeUtc )
				Console.WriteLine("testfile2 is newer.");
			else 
				Console.WriteLine("They're equal.");

			Console.ReadLine();

		}

[Shaitan00]

Sadly I am not using FileInfo but FILETIME instead - I am not actually comparing FILES but creation time from a REGISTRY KEY using my GetFileTime(&ft); function - there is no FileInfo equivalent so I needed to create FILETIME variables and I need to compare those...

So I really need to find a way to compare FILETIME's, if I can convert them into something else great but I can't change the fact that I am started with 2 FILETIME variables...

Thanks,

[nmadd]

Maybe this?
http://www.aspemporium.com/howto.aspx?hid=26