Int64::Parse Method (String^, NumberStyles)
Converts the string representation of a number in a specified style to its 64bit signed integer equivalent.
Assembly: mscorlib (in mscorlib.dll)
Parameters
 s

Type:
System::String^
A string containing a number to convert.
 style

Type:
System.Globalization::NumberStyles
A bitwise combination of NumberStyles values that indicates the permitted format of s. A typical value to specify is Integer.
Exception  Condition 

ArgumentNullException  s is null. 
ArgumentException  style is not a NumberStyles value. or style is not a combination of AllowHexSpecifier and HexNumber values. 
FormatException  s is not in a format compliant with style. 
OverflowException 
The style parameter defines the style elements (such as white space, the positive or negative sign symbol, or the thousands separator symbol) that are allowed in the s parameter for the parse operation to succeed. It must be a combination of bit flags from the NumberStyles enumeration. Depending on the value of style, the s parameter may contain the following elements:
[ws][$][sign][digits,]digits[.fractional_digits][e[sign]exponential_digits][ws]
Or, if style includes AllowHexSpecifier:
[ws]hexdigits[ws]
Elements in square brackets ([ and ]) are optional. The following table describes each element.
Element  Description 

ws  Optional white space. White space can appear at the beginning of s if style includes the NumberStyles::AllowLeadingWhite flag, and it can appear at the end of s if style includes the NumberStyles::AllowTrailingWhite flag. 
$  A culturespecific currency symbol. Its position in the string is defined by the NumberFormatInfo::CurrencyNegativePattern and NumberFormatInfo::CurrencyPositivePattern properties of the current culture. The current culture's currency symbol can appear in s if style includes the NumberStyles::AllowCurrencySymbol flag. 
sign  An optional sign. The sign can appear at the beginning of s if style includes the NumberStyles::AllowLeadingSign flag, and it can appear at the end of s if style includes the NumberStyles::AllowTrailingSign flag. Parentheses can be used in s to indicate a negative value if style includes the NumberStyles::AllowParentheses flag. 
digits fractional_digits exponential_digits  A sequence of digits from 0 through 9. For fractional_digits, only the digit 0 is valid. 
,  A culturespecific thousands separator symbol. The current culture's thousands separator can appear in s if style includes the NumberStyles::AllowThousands flag. 
.  A culturespecific decimal point symbol. The current culture's decimal point symbol can appear in s if style includes the NumberStyles::AllowDecimalPoint flag. Only the digit 0 can appear as a fractional digit for the parse operation to succeed; if fractional_digits includes any other digit, an OverflowException is thrown. 
e  The 'e' or 'E' character, which indicates that the value is represented in exponential notation. The s parameter can represent a number in exponential notation if style includes the NumberStyles::AllowExponent flag. 
hexdigits  A sequence of hexadecimal digits from 0 through f, or 0 through F. 
A string with digits only (which corresponds to the NumberStyles::None style) always parses successfully if it is in the range of the Int64 type. Most of the remaining NumberStyles members control elements that may be but are not required to be present in the input string. The following table indicates how individual NumberStyles members affect the elements that may be present in s.
NumberStyles value  Elements permitted in s in addition to digits 

The digits element only.  
The decimal point ( . ) and fractionaldigits elements.  
The s parameter can also use exponential notation. If s represents a number in exponential notation, the resulting numeric value cannot include any nonzero fractional digits.  
The ws element at the beginning of s.  
The ws element at the end of s.  
The sign element at the beginning of s.  
The sign element at the end of s.  
The sign element in the form of parentheses enclosing the numeric value.  
The thousands separator ( , ) element.  
The $ element.  
All. The s parameter cannot represent a hexadecimal number or a number in exponential notation.  
The ws element at the beginning or end of s, sign at the beginning of s, and the decimal point ( . ) symbol. The s parameter can also use exponential notation.  
The ws, sign, thousands separator ( , ), and decimal point ( . ) elements.  
All styles, except s cannot represent a hexadecimal number. 
If the NumberStyles::AllowHexSpecifier flag is used, s must be a hexadecimal value without a prefix. For example, "C9AF3" parses successfully, but "0xC9AF3" does not. The only other flags that can be combined with the s parameter are NumberStyles::AllowLeadingWhite and NumberStyles::AllowTrailingWhite. (The NumberStyles enumeration includes a composite number style, NumberStyles::HexNumber, that includes both white space flags.)
The s parameter is parsed using the formatting information in a NumberFormatInfo object that is initialized for the current system culture. To specify the culture whose formatting information is used for the parse operation, call the Int64::Parse(String^, NumberStyles, IFormatProvider^) overload.
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1