CFileTime Class

This class provides methods for managing the date and time values associated with the creation, access and modification of files. The methods and data of this class are frequently used in conjunction with CFileTimeSpan objects, which deal with relative time values.

The date and time value is stored as a 64-bit value representing the number of 100-nanosecond intervals since January 1, 1601. This is the Coordinated Universal Time (UTC) format.

The following static const member variables are provided to simplify calculations (number of 100-nanosecond intervals):

CFileTime_Millisecond    10,000
CFileTime_Second         CFileTime_Millisecond * 1,000
CFileTime_Minute         CFileTime_Second * 60
CFileTime_Hour           CFileTime_Minute * 60
CFileTime_Day            CFileTime_Hour * 24
CFileTime_Week           CFileTime_Day * 7

Note: Not all file systems can record creation and last access time and not all file systems record them in the same manner. For example, on the Windows NT FAT file system, create time has a resolution of 10 milliseconds, write time has a resolution of 2 seconds, and access time has a resolution of 1 day (the access date). On NTFS, access time has a resolution of 1 hour. Furthermore, FAT records times on disk in local time, but NTFS records times on disk in UTC.

CFileTimeSpan Class

This class provides methods for managing relative periods of time often encountered when performing operations concerning when a file was created, last accessed or last modified. The methods of this class are frequently used in conjunction with CFileTime class objects.

The CFileTimeSpan object can be created using an existing CFileTimeSpan object, or expressed as a 64-bit value. The default constructor sets the time span to 0.

Constructors (CFileTime)

Create new CFileTime objects initialized to the specified value.

CONSTRUCTOR CFileTime
CONSTRUCTOR CFileTime (BYVAL nSpan AS ULONGLONG)
CONSTRUCTOR CFileTime (BYREF ft AS FILETIME)
CONSTRUCTOR CFileTime (BYREF st AS SYSTEMTIME)

Examples

DIM cft AS CFileTime = CFileTime().GetCurrentTime()

DIM cft AS CFileTime = AfxLocalFileTime
print cft.GetTime

DIM cft AS CFileTime = AfxLocalSystemTime
print cft.GetTime

Constructors (CFileTimeSpan)

Create new CFileTimeSpan objects initialized to the specified value.

CONSTRUCTOR CFileTimeSpan
CONSTRUCTOR CFileTimeSpan (BYVAL nSpan AS ULONGLONG)
CONSTRUCTOR CFileTimeSpan (BYREF cSpan AS CFileTimeSpan)

Example

DIM cSpan AS CFileTimeSpan = CFileTime_Day

CAST Operator (CFileTime)

Returns the CFileTime value as a long integer.

OPERATOR CAST () AS LONGLONG

Examples

DIM cft AS CFileTime = CFileTime().GetCurrentTime()
DIM nTime AS LONGLONG = cft
print nTime

DIM cft AS CFileTime = CFileTime().GetCurrentTime()
DIM cft2 AS CFileTime = cft

CAST Operator (CFileTimeSpan)

Returns the CFileTimeSpan value as a long integer.

OPERATOR CAST () AS LONGLONG

LET Operator (=) (CFileTime)

Assigns a value to a CFileTime object.

OPERATOR LET (BYVAL nTime AS ULONGLONG)
OPERATOR LET (BYREF ft AS FILETIME)
OPERATOR LET (BYREF st AS SYSTEMTIME)

Examples

DIM cft AS CFileTime
cft = AfxLocalFileTime
print cft.GetTime

DIM cft AS CFileTime
cft = AfxLocalSystemTime
print cft.GetTime

LET Operator (=) (CFileTimeSpan)

Assigns a value to a CFileTimeSpan object.

OPERATOR LET (BYVAL nSpan AS LONGLONG)
OPERATOR LET (BYREF cSpan AS CFileTimeSpan)

Operators (CFileTime)

Adds, subtracts or compares CFileTime objects.

OPERATOR + (BYREF dt AS CFileTime, BYREF dateSpan AS CFileTimeSpan) AS CFileTime
OPERATOR - (BYREF dt AS CFileTime, BYREF dateSpan AS CFileTimeSpan) AS CFileTime
OPERATOR - (BYREF dt1 AS CFileTime, BYREF dt2 AS CFileTime) AS CFileTimeSpan
OPERATOR += (BYREF dateSpan AS CFileTimeSpan)
OPERATOR -= (BYREF dateSpan AS CFileTimeSpan)
OPERATOR = (BYREF dt1 AS CFileTime, BYREF dt2 AS CFileTime) AS BOOLEAN
OPERATOR <> (BYREF dt1 AS CFileTime, BYREF dt2 AS CFileTime) AS BOOLEAN
OPERATOR < (BYREF dt1 AS CFileTime, BYREF dt2 AS CFileTime) AS BOOLEAN
OPERATOR > (BYREF dt1 AS CFileTime, BYREF dt2 AS CFileTime) AS BOOLEAN
OPERATOR <= (BYREF dt1 AS CFileTime, BYREF dt2 AS CFileTime) AS BOOLEAN
OPERATOR >= (BYREF dt1 AS CFileTime, BYREF dt2 AS CFileTime) AS BOOLEAN

Operators (CFileTimeSpan)

Adds, subtracts or compares CFileTimeSpan objects.

OPERATOR + (BYREF cSpan1 AS CFileTimeSpan, BYREF cSpan2 AS CFileTimeSpan) AS CFileTimeSpan
OPERATOR - (BYREF cSpan1 AS CFileTimeSpan, BYREF cSpan2 AS CFileTimeSpan) AS CFileTimeSpan
OPERATOR += (BYREF dateSpan AS CFileTimeSpan)
OPERATOR -= (BYREF dateSpan AS CFileTimeSpan)
OPERATOR = (BYREF cSpan1 AS CFileTimeSpan, BYREF cSpan2 AS CFileTimeSpan) AS BOOLEAN
OPERATOR <> (BYREF cSpan1 AS CFileTimeSpan, BYREF cSpan2 AS CFileTimeSpan) AS BOOLEAN
OPERATOR < (BYREF cSpan1 AS CFileTimeSpan, BYREF cSpan2 AS CFileTimeSpan) AS BOOLEAN
OPERATOR > (BYREF cSpan1 AS CFileTimeSpan, BYREF cSpan2 AS CFileTimeSpan) AS BOOLEAN
OPERATOR <= (BYREF cSpan1 AS CFileTimeSpan, BYREF cSpan2 AS CFileTimeSpan) AS BOOLEAN
OPERATOR >= (BYREF cSpan1 AS CFileTimeSpan, BYREF cSpan2 AS CFileTimeSpan) AS BOOLEAN

Day (CFileTime / CFileTimeSpan)

Returns the number of 100-nanosecond intervals that make up one day.

FUNCTION Day () AS ULONGLONG

Hour (CFileTime / CFileTimeSpan)

Returns the number of 100-nanosecond intervals that make up one hour.

FUNCTION Hour () AS ULONGLONG

Millisecond (CFileTime / CFileTimeSpan)

Returns the number of 100-nanosecond intervals that make up one millisecond.

FUNCTION Millisecond () AS ULONGLONG

Minute (CFileTime / CFileTimeSpan)

Returns the number of 100-nanosecond intervals that make up one minute.

FUNCTION Minute () AS ULONGLONG

Second (CFileTime / CFileTimeSpan)

Returns the number of 100-nanosecond intervals that make up one second.

FUNCTION Second () AS ULONGLONG

Week (CFileTime / CFileTimeSpan)

Returns the number of 100-nanosecond intervals that make up one week.

FUNCTION Week () AS ULONGLONG

Format (CFileTime)

Converts a CFileTime object to a string.

FUNCTION Format (BYREF wszFmt AS WSTRING) AS CWSTR

Formatting codes:

The # flag may prefix any formatting code. In that case, the meaning of the format code is changed as follows.

• %#a, %#A, %#b, %#B, %#p, %#X, %#z, %#Z, %#%: # flag is ignored.
• %#c: Long date and time representation, appropriate for current locale. For example: "Tuesday, March 14, 1995, 12:41:29".
• %#x* Long date representation, appropriate to current locale. For example: "Tuesday, March 14, 1995".
• %#d, %#H, %#I, %#j, %#m, %#M, %#S, %#U, %#w, %#W, %#y, %#Y: Remove leading zeros (if any).

Remarks

Formats the value by using the format string which contains special formatting codes that are preceded by a percent sign (%).

Examples

print cft.Format("%A, %B %d, %Y %H:%M:%S")

DIM cft AS CFileTime
cft = AfxLocalFileTime
print cft.Format("%A, %B %d, %Y %H:%M:%S")

GetAsFileTime (CFileTime)

Returns the time as a FILETIME structure.

FUNCTION GetAsFileTime () AS FILETIME

GetAsSystemTime (CFileTime)

Returns the time as a SYSTEMTIME structure.

FUNCTION GetAsSystemTime () AS SYSTEMTIME

GetCurrentTime (CFileTime)

Returns a CFileTime object that represents the current system date and time.

FUNCTION GetCurrentTime () AS CFileTime

GetTime (CFileTime)

Returns the value of the CFileTime object.

FUNCTION GetTime () AS LONGLONG

Example

DIM cft AS CFileTime = CFileTime().GetCurrentTime()
print cft.GetTime

SetTime (CFileTime)

Sets the date and time of this CFileTime object

FUNCTION SetTime (BYVAL nTime AS ULONGLONG)

LocalToUTC (CFileTime)

Converts a local file time to a file time based on the Coordinated Universal Time (UTC).

FUNCTION LocalToUTC () AS CFileTime

UTCToLocal (CFileTime)

Converts time based on the Coordinated Universal Time (UTC) to local file time.

FUNCTION UTCToLocal () AS CFileTime

GetTimeSpan (CFileTimeSpan)

Returns the value of the CFileTimeSpan object.

FUNCTION GetTimeSpan () AS LONGLONG

SetTimeSpan (CFileTimeSpan)

Sets the date and time of this CFileTimeSpan object.

FUNCTION SetTimeSpan (BYVAL nSpan AS LONGLONG)