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,

[snarfblam]

You can import the CompareFileTime function from the Windows API to use it in C#.

 

 

C# Code[HorizontalRule]magic hidden text[/HorizontalRule][DllImport("kernel32.dll")]

static extern int CompareFileTime (

____ ref FILETIME lpFileTime1,

____ ref FILETIME lpFileTime2);

[HorizontalRule]Why are you quoting me?[/HorizontalRule]

 

Note that the reference operator in C++ becomes the ref keyword in C#...

 

 

C# Code[HorizontalRule]magic hidden text[/HorizontalRule]if (-1 == CompareFileTime (ref ftMostRecent, ref ft))

{

____ // ... do something ... //

}[HorizontalRule]Why are you quoting me?[/HorizontalRule]

[dynamic_sysop]

well you can use a couple of easy ways

way 1:

[size=2]
[/size][size=2][color=#2b91af]Console[/color][/size][size=2].WriteLine([/size][size=2][color=#2b91af]DateTime[/color][/size][size=2].Compare(System.IO.[/size][size=2][color=#2b91af]File[/color][/size][size=2].GetCreationTime([/size][size=2][color=#a31515]"C:\\B156_FSM.pdf"[/color][/size][size=2]), System.IO.[/size][size=2][color=#2b91af]File[/color][/size][size=2].GetCreationTime([/size][size=2][color=#a31515]"C:\\YServer.txt"[/color][/size][size=2])));
[/size]

basically you will get a return of 1 or -1 ( maybe 0 if both had identical times, but don't quote me on that )

way 2:

[size=2][/size][size=2][color=#2b91af]Console[/color][/size][size=2].WriteLine( [/size][size=2][color=#2b91af]DateTime[/color][/size][size=2].Compare([/size][size=2][color=#2b91af]DateTime[/color][/size][size=2].FromFileTime(' the long filetime value here !!! '), [/size][size=2][color=#2b91af]DateTime[/color][/size][size=2].FromFileTime(' the long filetime value here !!! ')) );
[/size][size=2][color=#008000][/color][/size]

hope it helps.