SByte.TryParse 方法

public:
 static bool TryParse(System::String ^ s, [Runtime::InteropServices::Out] System::SByte % result);

[System.CLSCompliant(false)]
public static bool TryParse (string s, out sbyte result);

public static bool TryParse (string? s, out sbyte? result);

[System.CLSCompliant(false)]
public static bool TryParse (string? s, out sbyte? result);

[<System.CLSCompliant(false)>]
static member TryParse : string * sbyte -> bool

static member TryParse : string * sbyte -> bool

Public Shared Function TryParse (s As String, ByRef result As SByte) As Boolean

参数

返回

Boolean

如果 true 成功转换，则为 s；否则为 false。true if s was converted successfully; otherwise, false.

属性

CLSCompliantAttribute

示例

下面的示例通过调用方法尝试将数组中的字符串转换为 SByte 值 TryParse(String, SByte) 。The following example tries to convert the strings in an array to SByte values by calling the TryParse(String, SByte) method.

string[] numericStrings = {"-3.6", "12.8", "+16.7", "    3   ", "(17)", 
                           "-17", "+12", "18-", "987", "1,024", "  127 "};
sbyte number;
foreach (string numericString in numericStrings)
{
   if (sbyte.TryParse(numericString, out number)) 
      Console.WriteLine("Converted '{0}' to {1}.", numericString, number);
   else
      Console.WriteLine("Cannot convert '{0}' to an SByte.", numericString);
}
// The example displays the following output to the console:
//       Cannot convert '-3.6' to an SByte.
//       Cannot convert '12.8' to an SByte.
//       Cannot convert '+16.7' to an SByte.
//       Converted '    3   ' to 3.
//       Cannot convert '(17)' to an SByte.
//       Converted '-17' to -17.
//       Converted '+12' to 12.
//       Cannot convert '18-' to an SByte.
//       Cannot convert '987' to an SByte.
//       Cannot convert '1,024' to an SByte.
//       Converted '  127 ' to 127.

Dim numericStrings() As String = {"-3.6", "12.8", "+16.7", "    3   ", _
                                  "(17)", "-17", "+12", "18-", "987", _
                                  "1,024", "  127 "}
Dim number As SByte
For Each numericString As String In numericStrings
   If SByte.TryParse(numericString, number) Then
      Console.WriteLine("Converted '{0}' to {1}.", numericString, number)
   Else
      Console.WriteLine("Cannot convert '{0}' to an SByte.", numericString)
   End If      
Next
' The example displays the following output to the console:
'       Cannot convert '-3.6' to an SByte.
'       Cannot convert '12.8' to an SByte.
'       Cannot convert '+16.7' to an SByte.
'       Converted '    3   ' to 3.
'       Cannot convert '(17)' to an SByte.
'       Converted '-17' to -17.
'       Converted '+12' to 12.
'       Cannot convert '18-' to an SByte.
'       Cannot convert '987' to an SByte.
'       Cannot convert '1,024' to an SByte.
'       Converted '  127 ' to 127.

注解

SByte.TryParse(String, SByte)方法与 SByte.Parse(String) 方法类似，不同之处在于它不会在转换失败时引发异常。The SByte.TryParse(String, SByte) method is like the SByte.Parse(String) method, except that it does not throw an exception if the conversion fails. 此方法无需使用异常处理来测试 FormatException if value 是否无效且无法成功分析。This method eliminates the need to use exception handling to test for a FormatException if value is invalid and cannot be successfully parsed.

s参数应为以下形式的十进制数的字符串表示形式：The s parameter should be the string representation of a decimal number in the following form:

[ws][sign]数字[ws][ws][sign]digits[ws]

方括号 ([ and ]) 中的元素是可选的。Elements in square brackets ([ and ]) are optional. 下表对每个元素进行了描述。The following table describes each element.

元素Element	说明Description
wsws	可选空白。Optional white space.
signsign	一个可选的符号。An optional sign. 有效的符号字符由 NumberFormatInfo.NegativeSign NumberFormatInfo.PositiveSign 当前区域性的和属性确定。Valid sign characters are determined by the NumberFormatInfo.NegativeSign and NumberFormatInfo.PositiveSign properties of the current culture.
位数digits	十进制数字的序列，范围为0到9。A sequence of decimal digits ranging from 0 to 9.

s使用样式对参数进行解释 NumberStyles.Integer 。The s parameter is interpreted by using the NumberStyles.Integer style. 除十进制数字外，只允许使用前导符号和尾随空格。In addition to the decimal digits, only leading and trailing spaces with a leading sign are allowed. 若要显式定义具有可在中存在的区域性特定格式设置信息的样式元素 value ，请调用 TryParse(String, NumberStyles, IFormatProvider, SByte) 方法。To explicitly define the style elements with the culture-specific formatting information that can be present in value, call the TryParse(String, NumberStyles, IFormatProvider, SByte) method.

s使用当前区域性的对象中的格式设置信息分析参数 NumberFormatInfo 。The s parameter is parsed by using the formatting information in a NumberFormatInfo object for the current culture. 有关详细信息，请参阅 NumberFormatInfo.CurrentInfo。For more information, see NumberFormatInfo.CurrentInfo.

此重载将参数中的所有数字解释 value 为十进制数字。This overload interprets all digits in the value parameter as decimal digits. 若要分析十六进制数的字符串表示形式，请改为调用 TryParse(String, NumberStyles, IFormatProvider, SByte) 重载。To parse the string representation of a hexadecimal number, call the TryParse(String, NumberStyles, IFormatProvider, SByte) overload instead.

另请参阅

• 示例：.NET Core WinForms 格式设置实用工具 (C#)Sample: .NET Core WinForms Formatting Utility (C#)
• 示例：.NET Core WinForms 格式设置实用工具 (Visual Basic)Sample: .NET Core WinForms Formatting Utility (Visual Basic)

public:
 static bool TryParse(ReadOnlySpan<char> s, [Runtime::InteropServices::Out] System::SByte % result);

public static bool TryParse (ReadOnlySpan<char> s, out sbyte result);

[System.CLSCompliant(false)]
public static bool TryParse (ReadOnlySpan<char> s, out sbyte result);

static member TryParse : ReadOnlySpan<char> * sbyte -> bool

[<System.CLSCompliant(false)>]
static member TryParse : ReadOnlySpan<char> * sbyte -> bool

Public Shared Function TryParse (s As ReadOnlySpan(Of Char), ByRef result As SByte) As Boolean

参数

返回

Boolean

如果 true 成功转换，则为 s；否则为 false。true if s was converted successfully; otherwise, false.

属性

CLSCompliantAttribute

public:
 static bool TryParse(System::String ^ s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::SByte % result);

[System.CLSCompliant(false)]
public static bool TryParse (string s, System.Globalization.NumberStyles style, IFormatProvider provider, out sbyte result);

public static bool TryParse (string? s, System.Globalization.NumberStyles style, IFormatProvider? provider, out sbyte? result);

[System.CLSCompliant(false)]
public static bool TryParse (string? s, System.Globalization.NumberStyles style, IFormatProvider? provider, out sbyte? result);

[<System.CLSCompliant(false)>]
static member TryParse : string * System.Globalization.NumberStyles * IFormatProvider * sbyte -> bool

static member TryParse : string * System.Globalization.NumberStyles * IFormatProvider * sbyte -> bool

Public Shared Function TryParse (s As String, style As NumberStyles, provider As IFormatProvider, ByRef result As SByte) As Boolean

参数

返回

Boolean

如果 true 成功转换，则为 s；否则为 false。true if s was converted successfully; otherwise, false.

属性

CLSCompliantAttribute

例外

示例

下面的示例 TryParse(String, NumberStyles, IFormatProvider, SByte) 使用多个不同的字符串和值调用方法 NumberStyles 。The following example calls the TryParse(String, NumberStyles, IFormatProvider, SByte) method with a number of different string and NumberStyles values.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      string numericString;
      NumberStyles styles;
      
      numericString = "106";
      styles = NumberStyles.Integer;
      CallTryParse(numericString, styles);
      
      numericString = "-106";
      styles = NumberStyles.None;
      CallTryParse(numericString, styles);
      
      numericString = "103.00";
      styles = NumberStyles.Integer | NumberStyles.AllowDecimalPoint;
      CallTryParse(numericString, styles);
      
      numericString = "103.72";
      styles = NumberStyles.Integer | NumberStyles.AllowDecimalPoint;
      CallTryParse(numericString, styles);

      numericString = "10E-01";
      styles = NumberStyles.Integer | NumberStyles.AllowExponent;
      CallTryParse(numericString, styles); 
      
      numericString = "12E-01";
      CallTryParse(numericString, styles);
          
      numericString = "12E01";
      CallTryParse(numericString, styles); 
      
      numericString = "C8";
      CallTryParse(numericString, NumberStyles.HexNumber);
      
      numericString = "0x8C";
      CallTryParse(numericString, NumberStyles.HexNumber);
   }
   
   private static void CallTryParse(string stringToConvert, NumberStyles styles)
   {
      sbyte number;
      bool result = SByte.TryParse(stringToConvert, styles, 
                                   CultureInfo.InvariantCulture, out number);
      if (result)
         Console.WriteLine("Converted '{0}' to {1}.", stringToConvert, number);
      else
         Console.WriteLine("Attempted conversion of '{0}' failed.", 
                           Convert.ToString(stringToConvert));
   }
}
// The example displays the following output:
//       Converted '106' to 106.
//       Attempted conversion of '-106' failed.
//       Converted '103.00' to 103.
//       Attempted conversion of '103.72' failed.
//       Converted '10E-01' to 1.
//       Attempted conversion of '12E-01' failed.
//       Converted '12E01' to 120.
//       Converted 'C8' to -56.
//       Attempted conversion of '0x8C' failed.

Imports System.Globalization

Module StringParsing
   Public Sub Main()
      Dim numericString As String
      Dim styles As NumberStyles
      
      numericString = "106"
      styles = NumberStyles.Integer
      CallTryParse(numericString, styles)
      
      numericString = "-106"
      styles = NumberStyles.None
      CallTryParse(numericString, styles)
      
      numericString = "103.00"
      styles = NumberStyles.Integer Or NumberStyles.AllowDecimalPoint
      CallTryParse(numericString, styles)
      
      numericString = "103.72"
      styles = NumberStyles.Integer Or NumberStyles.AllowDecimalPoint
      CallTryParse(numericString, styles)

      numericString = "10E-01"
      styles = NumberStyles.Integer Or NumberStyles.AllowExponent
      CallTryParse(numericString, styles) 
      
      numericString = "12E-01"
      CallTryParse(numericString, styles)
          
      numericString = "12E01"
      CallTryParse(numericString, styles) 
      
      numericString = "C8"
      CallTryParse(numericString, NumberStyles.HexNumber)
      
      numericString = "0x8C"
      CallTryParse(numericString, NumberStyles.HexNumber)
   End Sub
   
   Private Sub CallTryParse(stringToConvert As String, styles AS NumberStyles)
      Dim number As SByte
      Dim result As Boolean = SByte.TryParse(stringToConvert, styles, _
                                             CultureInfo.InvariantCulture, number)
      If result Then
         Console.WriteLine("Converted '{0}' to {1}.", stringToConvert, number)
      Else
         Console.WriteLine("Attempted conversion of '{0}' failed.", _
                           Convert.ToString(stringToConvert))
      End If                                                                           
   End Sub
End Module
' The example displays the following output to the console:
'       Converted '106' to 106.
'       Attempted conversion of '-106' failed.
'       Converted '103.00' to 103.
'       Attempted conversion of '103.72' failed.
'       Converted '10E-01' to 1.
'       Attempted conversion of '12E-01' failed.
'       Converted '12E01' to 120.
'       Converted 'C8' to -56.
'       Attempted conversion of '0x8C' failed.

注解

TryParse(String, NumberStyles, IFormatProvider, SByte)方法与 Parse(String, NumberStyles, IFormatProvider) 方法类似，不同之处在于它不会在转换失败时引发异常。The TryParse(String, NumberStyles, IFormatProvider, SByte) method is like the Parse(String, NumberStyles, IFormatProvider) method, except that it does not throw an exception if the conversion fails. 此方法无需使用异常处理来测试是否 FormatException value 无效，并且无法成功分析。This method eliminates the need to use exception handling to test for a FormatException if value is invalid and cannot be parsed successfully.

style参数定义 (（如空白）或正号或负号) 等样式元素，以便 value 分析操作成功。The style parameter defines the style elements (such as white space or a positive or negative sign) that are allowed in the value parameter for the parse operation to succeed. 它必须是枚举中的位标志的组合 NumberStyles 。It must be a combination of bit flags from the NumberStyles enumeration. 根据的值 style ， value 参数可能包括以下元素：Depending on the value of style, the value parameter may include the following elements:

[ws][ $ ] [sign] [数字，]位数[。fractional_digits] [E [sign]exponential_digits] [ws][ws][$][sign][digits,]digits[.fractional_digits][E[sign]exponential_digits][ws]

如果 style 参数包含 AllowHexSpecifier ， value 参数可能包括以下元素：If the style parameter includes AllowHexSpecifier, the value parameter may include the following elements:

[ws]hexdigits[ws][ws]hexdigits[ws]

方括号 ([ and ]) 中的元素是可选的。Elements in square brackets ([ and ]) are optional. 下表对每个元素进行了描述。The following table describes each element.

元素Element	说明Description
wsws	可选空白。Optional white space. 如果包含标志，则可以在的开头出现空格; value style NumberStyles.AllowLeadingWhite value 如果包含标志，则为末尾处 style NumberStyles.AllowTrailingWhite 。White space can appear at the start of value if style includes the NumberStyles.AllowLeadingWhite flag, or at the end of value if style includes the NumberStyles.AllowTrailingWhite flag.
$	区域性特定的货币符号。A culture-specific currency symbol. 其在字符串中的位置由 CurrencyPositivePattern NumberFormatInfo 参数方法返回的对象的属性定义 GetFormat provider 。Its position in the string is defined by the CurrencyPositivePattern property of the NumberFormatInfo object returned by the GetFormat method of the provider parameter. value如果包含标志，则货币符号可以出现在中 style NumberStyles.AllowCurrencySymbol 。The currency symbol can appear in value if style includes the NumberStyles.AllowCurrencySymbol flag.
signsign	一个可选的符号。An optional sign. 如果包含标志，则符号可以出现在的开头 value style NumberStyles.AllowLeadingSign ，如果包含标志，则它可以出现在的结尾 value style NumberStyles.AllowTrailingSign 。The sign can appear at the start of value if style includes the NumberStyles.AllowLeadingSign flag, and it can appear at the end of value if style includes the NumberStyles.AllowTrailingSign flag. 如果包含标志，则可以在中使用括号 value 来表示负值 style NumberStyles.AllowParentheses 。Parentheses can be used in value to indicate a negative value if style includes the NumberStyles.AllowParentheses flag.
位数digits	介于0到9之间的一系列数字。A sequence of digits from 0 through 9.
,,	区域性特定的组分隔符。A culture-specific group separator. 如果包含标志，则所指定的区域性的组分隔符 provider 可以出现在中 value style NumberStyles.AllowThousands 。The group separator of the culture specified by provider can appear in value if style includes the NumberStyles.AllowThousands flag.
..	区域性特定的小数点符号。A culture-specific decimal point symbol. 如果包含标志，则指定的区域性的小数点符号 provider 可以出现在中 value style NumberStyles.AllowDecimalPoint 。The decimal point symbol of the culture specified by provider can appear in value if style includes the NumberStyles.AllowDecimalPoint flag.
fractional_digitsfractional_digits	数字0的一个或多个匹配项。One or more occurrences of the digit 0. value仅当包含标志时，小数位才能出现在中 style NumberStyles.AllowDecimalPoint 。Fractional digits can appear in value only if style includes the NumberStyles.AllowDecimalPoint flag.
EE	"E" 或 "E" 字符，指示以指数 (科学) 记数法表示的值。The "e" or "E" character, which indicates that the value is represented in exponential (scientific) notation. value如果包含标志，则参数可以表示指数表示法中的数字 style NumberStyles.AllowExponent 。The value parameter can represent a number in exponential notation if style includes the NumberStyles.AllowExponent flag.
exponential_digitsexponential_digits	介于0到9之间的一系列数字。A sequence of digits from 0 through 9. value如果包含标志，则参数可以表示指数表示法中的数字 style NumberStyles.AllowExponent 。The value parameter can represent a number in exponential notation if style includes the NumberStyles.AllowExponent flag.
hexdigitshexdigits	从0到 f 的十六进制数字序列，或者从0到 F。A sequence of hexadecimal digits from 0 through f, or 0 through F.

只包含十进制数字的字符串 (对应于 NumberStyles.None 标记) 总是成功分析。A string with decimal digits only (which corresponds to the NumberStyles.None flag) always parses successfully. 大多数其余 NumberStyles 成员控件在此输入字符串中可能存在但并不需要存在的元素。Most of the remaining NumberStyles members control elements that may be present, but are not required to be present, in this input string. 下表指示各个成员如何 NumberStyles 影响可能出现在中的元素 value 。The following table indicates how individual NumberStyles members affect the elements that may be present in value.

非复合 NumberStyles 值Non-composite NumberStyles values	除了数字以外，还允许在值中使用元素Elements permitted in value in addition to digits
None	仅十进制数字。Decimal digits only.
AllowDecimalPoint	小数点 () 和 fractional_digits 元素。The decimal point (.) and fractional_digits elements. 但 fractional_digits 只能包含一个或多个0位数字，否则该方法将返回 false 。However, fractional_digits must consist of only one or more 0 digits, or the method returns false.
AllowExponent	"E" 或 "E" 字符（指示指数表示法）以及 exponential_digits。The "e" or "E" character, which indicates exponential notation, along with exponential_digits. 如果 value 表示指数表示法中的数字，则它不能包含非零的小数部分。If value represents a number in exponential notation, it cannot have a non-zero, fractional component.
AllowLeadingWhite	开头的 ws 元素 value 。The ws element at the start of value.
AllowTrailingWhite	末尾处的 ws 元素 value 。The ws element at the end of value.
AllowLeadingSign	数字 前面的 sign 元素。The sign element before digits.
AllowTrailingSign	数字 后的 符号 元素。The sign element after digits.
AllowParentheses	用括号括起数值的 符号 元素。The sign element in the form of parentheses enclosing the numeric value.
AllowThousands	组分隔符 (，) 元素。The group separator (,) element.
AllowCurrencySymbol	货币 ($) 元素。The currency ($) element.
Currency	所有元素。All elements. 但是， value 不能表示十六进制数或以指数表示法表示的数字。However, value cannot represent a hexadecimal number or a number in exponential notation.
Float	开头或结尾处的 ws 元素，在 value 的开头处进行 签名， value 小数点 () 符号。 The ws element at the start or end of value, sign at the start of value, and the decimal point (.) symbol. value参数还可以使用指数表示法。The value parameter can also use exponential notation.
Number	Ws、 sign、group 分隔符 (、) 和 小数点 () 元素。The ws, sign, group separator (,), and decimal point (.) elements.
Any	所有元素。All elements. 但是， value 不能表示十六进制数。However, value cannot represent a hexadecimal number.

如果 NumberStyles.AllowHexSpecifier 使用标志，则 value 必须是十六进制值。If the NumberStyles.AllowHexSpecifier flag is used, value must be a hexadecimal value. 有效的十六进制数字为0-9、a-f 和 A-f。Valid hexadecimal digits are 0-9, a-f, and A-F. 中可以存在的唯一其他标志 style 是 NumberStyles.AllowLeadingWhite 和 NumberStyles.AllowTrailingWhite 。The only other flags that can be present in style are NumberStyles.AllowLeadingWhite and NumberStyles.AllowTrailingWhite. (NumberStyles 枚举具有复合样式， HexNumber 其中包含两个空白标志。 ) (The NumberStyles enumeration has a composite style, HexNumber, that includes both white-space flags.)

provider参数是一个 IFormatProvider 实现。The provider parameter is an IFormatProvider implementation. 其 GetFormat 方法返回一个 NumberFormatInfo 对象，该对象提供有关格式的区域性特定信息 value 。Its GetFormat method returns a NumberFormatInfo object that provides culture-specific information about the format of value. provider参数可以是以下任一项：The provider parameter can be any one of the following:

• 一个 CultureInfo 对象，该对象表示提供格式设置信息的区域性。A CultureInfo object that represents the culture that supplies formatting information. 其 GetFormat 方法返回 NumberFormatInfo 对象，该对象提供该区域性的数字格式设置信息。Its GetFormat method returns the NumberFormatInfo object that provides numeric formatting information for that culture.

• NumberFormatInfo提供数字格式设置信息的对象。A NumberFormatInfo object that provides numeric formatting information. (其实现 GetFormat 仅返回自身。 ) (Its implementation of GetFormat just returns itself.)

• 实现的自定义对象 IFormatProvider 。A custom object that implements IFormatProvider. 它的 GetFormat 方法实例化并返回 NumberFormatInfo 提供格式设置信息的对象。Its GetFormat method instantiates and returns the NumberFormatInfo object that provides formatting information.

如果 provider 为 null ，则 NumberFormatInfo 使用当前区域性的对象。If provider is null, the NumberFormatInfo object for the current culture is used.

另请参阅

• Parse(String, NumberStyles, IFormatProvider)
• 分析 .NET 中的数字字符串Parsing Numeric Strings in .NET

public:
 static bool TryParse(ReadOnlySpan<char> s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::SByte % result);

public static bool TryParse (ReadOnlySpan<char> s, System.Globalization.NumberStyles style, IFormatProvider? provider, out sbyte result);

[System.CLSCompliant(false)]
public static bool TryParse (ReadOnlySpan<char> s, System.Globalization.NumberStyles style, IFormatProvider provider, out sbyte result);

[System.CLSCompliant(false)]
public static bool TryParse (ReadOnlySpan<char> s, System.Globalization.NumberStyles style, IFormatProvider? provider, out sbyte result);

static member TryParse : ReadOnlySpan<char> * System.Globalization.NumberStyles * IFormatProvider * sbyte -> bool

[<System.CLSCompliant(false)>]
static member TryParse : ReadOnlySpan<char> * System.Globalization.NumberStyles * IFormatProvider * sbyte -> bool

Public Shared Function TryParse (s As ReadOnlySpan(Of Char), style As NumberStyles, provider As IFormatProvider, ByRef result As SByte) As Boolean

参数

返回

Boolean

如果 true 成功转换，则为 s；否则为 false。true if s was converted successfully; otherwise, false.

属性

CLSCompliantAttribute