The DateTimeOffset.ParseExact(string, string, IFormatProvider, System.Globalization.DateTimeStyles) method parses the string representation of a date, which must be in the format defined by the format parameter. It also requires that the <Date>, <Time>, and <Offset> elements of the string representation of a date and time appear in the order specified by format. If the input string does not match the pattern of the format parameter, with any variations defined by the styles parameter, the method throws a FormatException. In contrast, the DateTimeOffset.Parse(string, IFormatProvider, System.Globalization.DateTimeStyles) method parses the string representation of a date in any one of the formats recognized by the format provider's System.Globalization.DateTimeFormatInfo object. DateTimeOffset.Parse(string, IFormatProvider, System.Globalization.DateTimeStyles) also allows the <Date>, <Time>, and <Offset> elements of the string representation of a date and time to appear in any order.

The format parameter is a string that contains either a single standard format specifier or one or more custom format specifiers that define the required pattern of the input parameter. For details about valid formatting codes, see Standard DateTime Format Strings and Custom DateTime Format Strings. If format includes the z, zz, or zzz custom format specifiers to indicate that an offset must be present in input, that offset must include either a negative sign or a positive sign. If the sign is missing, the method throws a FormatException.

If format requires that input contain a date but not a time, the resulting DateTimeOffset object is assigned a time of midnight (0:00:00). If format requires that input contain a time but not a date, the resulting DateTimeOffset object is assigned the current date on the local system. If format does not require that input contain an offset, the offset of the resulting DateTimeOffset object depends on the value of the styles parameter. If styles includes System.Globalization.DateTimeStyles.AssumeLocal, the offset of the local time zone is assigned to the DateTimeOffset object. If styles includes System.Globalization.DateTimeStyles.AssumeUniversal, the Coordinated Universal Time (UTC) offset, or +00:00, is assigned to the DateTimeOffset object. If neither value is specified, the offset of the local time zone is used.

The particular date and time symbols and strings used in input are defined by the formatProvider parameter. The same is true for the precise format of input, if format is a standard format specifier string. The formatProvider parameter can be either of the following:

• A System.Globalization.CultureInfo object that represents the culture based on which input is interpreted. The System.Globalization.DateTimeFormatInfo object returned by the System.Globalization.CultureInfo.DateTimeFormat property defines the symbols and formatting in input.

• A System.Globalization.DateTimeFormatInfo object that defines the format of date and time data.

If formatprovider is null, the System.Globalization.CultureInfo object that corresponds to the current culture is used.

The styles parameter defines whether white space is allowed in the input string, indicates how strings without an explicit offset component are parsed, and supports UTC conversion as part of the parsing operation. All members of the System.Globalization.DateTimeStyles enumeration are supported except System.Globalization.DateTimeStyles.NoCurrentDateDefault. The following table lists the effect of each supported member.

System.Globalization.DateTimeStyles.AdjustToUniversal	Parses input and, if necessary, converts it to UTC. It is equivalent to parsing a string, and then calling the DateTimeOffset.ToUniversalTime method of the returned DateTimeOffset object.
System.Globalization.DateTimeStyles.AssumeLocal	If format does not require that input contain an offset value, the returned DateTimeOffset object is given the offset of the local time zone. This is the default value.
System.Globalization.DateTimeStyles.AssumeUniversal	If format does not require that input contain an offset value, the returned DateTimeOffset object is given the UTC offset (+00:00).
System.Globalization.DateTimeStyles.AllowInnerWhite	Allows input to include inner white space not specified by format. Extra white space can appear between date and time components and within individual components, and is ignored when parsing the string.
System.Globalization.DateTimeStyles.AllowLeadingWhite	Allows input to include leading spaces not specified by format. These are ignored when parsing the string.
System.Globalization.DateTimeStyles.AllowTrailingWhite	Allows input to include trailing spaces not specified by format. These are ignored when parsing the string.
System.Globalization.DateTimeStyles.AllowWhiteSpaces	Allows input to include leading, trailing, and inner spaces not specified by format. All extra white-space characters not specified in format are ignored when parsing the string.
System.Globalization.DateTimeStyles.None	Indicates that additional white space is not permitted in input. White space must appear exactly as specified in format. This is the default behavior.
System.Globalization.DateTimeStyles.RoundtripKind	Has no effect because the DateTimeOffset structure does not include a Kind property.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 2.0.0.0, 4.0.0.0