CFileTime Class

Members (26)

Documentation

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. A nanosecond is one-billionth of a second.

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

CFileTime_Millisecond    10000ull
CFileTime_Second         CFileTime_Millisecond * 1000
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.

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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.

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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

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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

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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

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CAST Operator (CFileTimeSpan)

Returns the CFileTimeSpan value as a long integer.

OPERATOR CAST () AS LONGLONG

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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

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LET Operator (=) (CFileTimeSpan)

Assigns a value to a CFileTimeSpan object.

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

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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

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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

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Day (CFileTime / CFileTimeSpan)

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

FUNCTION Day () AS ULONGLONG

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Hour (CFileTime / CFileTimeSpan)

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

FUNCTION Hour () AS ULONGLONG

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Millisecond (CFileTime / CFileTimeSpan)

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

FUNCTION Millisecond () AS ULONGLONG

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Minute (CFileTime / CFileTimeSpan)

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

FUNCTION Minute () AS ULONGLONG

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Second (CFileTime / CFileTimeSpan)

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

FUNCTION Second () AS ULONGLONG

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Week (CFileTime / CFileTimeSpan)

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

FUNCTION Week () AS ULONGLONG

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DateString

Returns the date as a string based on the specified mask, e.g. "dd-MM-yyyy".

FUNCTION DateString (BYREF wszMask AS WSTRING, BYVAL lcid AS LCID = LOCALE_USER_DEFAULT) AS DWSTRING

The following table defines the format types used to represent days.

The following table defines the format types used to represent months.

The following table defines the format types used to represent years.

Return value

The formatted date.

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TimeString

Returns the time as a string based on the specified mask, e.g. "hh':'mm':'ss".

FUNCTION TimeString (BYREF wszMask AS WSTRING, BYVAL lcid AS LCID = LOCALE_USER_DEFAULT) AS DWSTRING

The application can use the following elements to construct a format picture string. If spaces are used to separate the elements in the format string, these spaces appear in the same location in the output string. The letters must be in uppercase or lowercase as shown, for example, "ss", not "SS". Characters in the format string that are enclosed in single quotation marks appear in the same location and unchanged in the output string.

Return value

The formatted time.

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Format (CFileTime)

Converts a CFileTime object to a string.

FUNCTION Format (BYREF wszFmt AS WSTRING) AS DWSTRING

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")

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GetAsFileTime (CFileTime)

Returns the time as a FILETIME structure.

FUNCTION GetAsFileTime () AS FILETIME

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GetAsSystemTime (CFileTime)

Returns the time as a SYSTEMTIME structure.

FUNCTION GetAsSystemTime () AS SYSTEMTIME

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GetCurrentTime (CFileTime)

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

FUNCTION GetCurrentTime () AS CFileTime

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GetTime (CFileTime)

Returns the value of the CFileTime object.

FUNCTION GetTime () AS LONGLONG

Example

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

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SetTime (CFileTime)

Sets the date and time of this CFileTime object

FUNCTION SetTime (BYVAL nTime AS ULONGLONG)

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LocalToUTC (CFileTime)

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

FUNCTION LocalToUTC () AS CFileTime

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UTCToLocal (CFileTime)

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

FUNCTION UTCToLocal () AS CFileTime

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GetTimeSpan (CFileTimeSpan)

Returns the value of the CFileTimeSpan object.

FUNCTION GetTimeSpan () AS LONGLONG

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SetTimeSpan (CFileTimeSpan)

Sets the date and time of this CFileTimeSpan object.

FUNCTION SetTimeSpan (BYVAL nSpan AS LONGLONG)

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