DateTime.ParseExact Method (String, String, IFormatProvider, DateTimeStyles)
Converts the specified string representation of a date and time to its DateTime equivalent using the specified array of formats, culture-specific format information, and style. The format of the string representation must match at least one of the specified formats exactly or an exception is thrown.
Assembly: mscorlib (in mscorlib.dll)
static member ParseExact : s:string * formats:string * provider:IFormatProvider * style:DateTimeStyles -> DateTime
- Type: System.String
A string that contains a date and time to convert.
- Type: System.String
An array of allowable formats of s. For more information, see the Remarks section.
- Type: System.IFormatProvider
An object that supplies culture-specific format information about s.
Return ValueType: System.DateTime
An object that is equivalent to the date and time contained in s, as specified by formats, provider, and style.
s or formats is a null reference (Nothing in Visual Basic).
s is an empty string.
an element of formats is an empty string.
s does not contain a date and time that corresponds to any element of formats.
The hour component and the AM/PM designator in s do not agree.
The method parses the string representation of a date that matches any one of the patterns assigned to the formats parameter. If the string s does not match any one of these patterns with any of the variations defined by the styles parameter, the method throws a FormatException. Aside from comparing s to multiple formatting patterns, rather than to a single formatting pattern, this overload behaves identically to the DateTime.ParseExact(String, String, IFormatProvider, DateTimeStyles) method.
The s parameter contains the date and time to parse. If the s parameter contains only a time and no date, the current date is used unless the style parameter includes the DateTimeStyles.NoCurrentDateDefault flag, in which case the default date (DateTime.Date.MinValue) is used. If the s parameter contains only a date and no time, midnight (00:00:00) is used. The style parameter also determines whether the s parameter can contain leading, inner, or trailing white space characters other than those permitted by one of the format strings in formats.
If s contains no time zone information, the Kind property of the returned DateTime object is DateTimeKind.Unspecified. This behavior can be changed by using the DateTimeStyles.AssumeLocal flag, which returns a DateTime value whose Kind property is DateTimeKind.Local, or by using the DateTimeStyles.AssumeUniversal and DateTimeStyles.AdjustToUniversal flags, which returns a DateTime value whose Kind property is DateTimeKind.Utc. If s contains time zone information, the time is converted to local time, if necessary, and the Kind property of the returned DateTime object is set to DateTimeKind.Local. This behavior can be changed by using the DateTimeStyles.RoundtripKind flag to not convert Coordinated Universal Time (UTC) to a local time and set the Kind property to DateTimeKind.Utc.
The formats parameter contains an array of patterns, one of which s must match exactly if the parse operation is to succeed. The patterns in the formats parameter consists of one or more custom format specifiers from the Custom Date and Time Format Strings table, or a single standard format specifier, which identifies a predefined pattern, from the Standard Date and Time Format Strings table.
If you do not use date or time separators in a custom format pattern, use the invariant culture for the provider parameter and the widest form of each custom format specifier. For example, if you want to specify hours in the pattern, specify the wider form, "HH", instead of the narrower form, "H".
The styles parameter includes one or more members of the DateTimeStyles enumeration that determine whether and where white space not defined by format can appear in s and that control the precise behavior of the parse operation. The following table describes how each member of the DateTimeStyles enumeration affects the operation of the ParseExact(String, String, IFormatProvider, DateTimeStyles) method.
Parses s and, if necessary, converts it to UTC. If s includes a time zone offset, or if s contains no time zone information but styles includes the DateTimeStyles.AssumeLocal flag, the method parses the string, calls ToUniversalTime to convert the returned DateTime value to UTC, and sets the Kind property to DateTimeKind.Utc. If s indicates that it represents UTC, or if s does not contain time zone information but styles includes the DateTimeStyles.AssumeUniversal flag, the method parses the string, performs no time zone conversion on the returned DateTime value, and sets the Kind property to DateTimeKind.Utc. In all other cases, the flag has no effect.
Specifies that white space not defined by format can appear between any individual date or time element.
Specifies that white space not defined by format can appear at the beginning of s.
Specifies that white space not defined by format can appear at the end of s.
Specifies that s may contain leading, inner, and trailing white spaces not defined by format.
Specifies that if s lacks any time zone information, it is assumed to represent a local time. Unless the DateTimeStyles.AdjustToUniversal flag is present, the Kind property of the returned DateTime value is set to DateTimeKind.Local.
Specifies that if s lacks any time zone information, it is assumed to represent UTC. Unless the DateTimeStyles.AdjustToUniversal flag is present, the method converts the returned DateTime value from UTC to local time and sets its Kind property to DateTimeKind.Local.
If s contains time without date information, the date of the return value is set to DateTime.MinValue.Date.
The s parameter is parsed using default values. No white space other than that present in format is allowed. If s lacks a date component, the date of the returned DateTime value is set to 1/1/0001. If s contains no time zone information, the Kind property of the returned DateTime object is set to DateTimeKind.Unspecified. If time zone information is present in s, the time is converted to local time and the Kind property of the returned DateTime object is set to DateTimeKind.Local.
For strings that contain time zone information, tries to prevent the conversion to a date and time with its Kind property set to DateTimeKind.Local. This flag primarily prevents the conversion of UTC times to local times.
The particular date and time symbols and strings (such as the names of the days of the week in a particular language) used in s are defined by the provider parameter, as is the precise format of s if format is a standard format specifier string. The provider parameter can be any of the following:
A DateTimeFormatInfo object that defines the format of date and time data.
If provider is a null reference (Nothing in Visual Basic), the CultureInfo object that corresponds to the current culture is used.Notes to Callers
In the .NET Framework 4, the ParseExact method throws a FormatException if the string to be parsed contains an hour component and an AM/PM designator that are not in agreement. In the .NET Framework 3.5 and earlier versions, the AM/PM designator is ignored.