# Boolean 結構

## 定義

``public value class Boolean : IComparable, IComparable<bool>, IConvertible, IEquatable<bool>``
``public struct Boolean : IComparable, IComparable<bool>, IConvertible, IEquatable<bool>``
``````[System.Serializable]
public struct Boolean : IComparable, IComparable<bool>, IConvertible, IEquatable<bool>``````
``````[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public struct Boolean : IComparable, IComparable<bool>, IConvertible, IEquatable<bool>``````
``````type bool = struct
interface IConvertible``````
``````Public Structure Boolean
Implements IComparable, IComparable(Of Boolean), IConvertible, IEquatable(Of Boolean)``````

Boolean

## 備註

Boolean 實例可以有兩個值的其中一個： `true``false`A Boolean instance can have either of two values: `true`, or `false`.

Boolean 結構提供支援下列工作的方法：The Boolean structure provides methods that support the following tasks:

### 格式化布林值Formatting Boolean values

Boolean 的字串表示 `true` 值為 "True"，若為 `false` 值，則為 "False"。The string representation of a Boolean is either "True" for a `true` value or "False" for a `false` value. Boolean 值的字串表示是由唯讀的 TrueStringFalseString 欄位所定義。The string representation of a Boolean value is defined by the read-only TrueString and FalseString fields.

``````using System;

public class Example
{
public static void Main()
{
bool raining = false;
bool busLate = true;

Console.WriteLine("It is raining: {0}", raining);
Console.WriteLine("The bus is late: {0}", busLate);
}
}
// The example displays the following output:
//       It is raining: False
//       The bus is late: True
``````
``````Module Example
Public Sub Main()
Dim raining As Boolean = False
Dim busLate As Boolean = True

Console.WriteLine("It is raining: {0}", raining)
Console.WriteLine("The bus is late: {0}", busLate)
End Sub
End Module
' The example displays the following output:
'       It is raining: False
'       The bus is late: True
``````

``````using System;

public class Example
{
public static void Main()
{
bool raining = false;
bool busLate = true;

Console.WriteLine("It is raining: {0}",
raining ? "Yes" : "No");
Console.WriteLine("The bus is late: {0}",
busLate ? "Yes" : "No" );
}
}
// The example displays the following output:
//       It is raining: No
//       The bus is late: Yes
``````
``````Module Example
Public Sub Main()
Dim raining As Boolean = False
Dim busLate As Boolean = True

Console.WriteLine("It is raining: {0}",
If(raining, "Yes", "No"))
Console.WriteLine("The bus is late: {0}",
If(busLate, "Yes", "No"))
End Sub
End Module
' The example displays the following output:
'       It is raining: No
'       The bus is late: Yes
``````

``````using System;
using System.Globalization;

public class Example
{
public static void Main()
{
String[] cultureNames = { "", "en-US", "fr-FR", "ru-RU" };
foreach (var cultureName in cultureNames) {
bool value = true;
CultureInfo culture = CultureInfo.CreateSpecificCulture(cultureName);
BooleanFormatter formatter = new BooleanFormatter(culture);

String result = String.Format(formatter, "Value for '{0}': {1}", culture.Name, value);
Console.WriteLine(result);
}
}
}

public class BooleanFormatter : ICustomFormatter, IFormatProvider
{
private CultureInfo culture;

public BooleanFormatter() : this(CultureInfo.CurrentCulture)
{ }

public BooleanFormatter(CultureInfo culture)
{
this.culture = culture;
}

public Object GetFormat(Type formatType)
{
if (formatType == typeof(ICustomFormatter))
return this;
else
return null;
}

public String Format(String fmt, Object arg, IFormatProvider formatProvider)
{
// Exit if another format provider is used.
if (! formatProvider.Equals(this)) return null;

// Exit if the type to be formatted is not a Boolean
if (! (arg is Boolean)) return null;

bool value = (bool) arg;
switch (culture.Name) {
case "en-US":
return value.ToString();
case "fr-FR":
if (value)
return "vrai";
else
return "faux";
case "ru-RU":
if (value)
return "верно";
else
return "неверно";
default:
return value.ToString();
}
}
}
// The example displays the following output:
//       Value for '': True
//       Value for 'en-US': True
//       Value for 'fr-FR': vrai
//       Value for 'ru-RU': верно
``````
``````Imports System.Globalization

Module Example
Public Sub Main()
Dim cultureNames() As String = { "", "en-US", "fr-FR", "ru-RU" }
For Each cultureName In cultureNames
Dim value As Boolean = True
Dim culture As CultureInfo = CultureInfo.CreateSpecificCulture(cultureName)
Dim formatter As New BooleanFormatter(culture)

Dim result As String = String.Format(formatter, "Value for '{0}': {1}", culture.Name, value)
Console.WriteLine(result)
Next
End Sub
End Module

Public Class BooleanFormatter
Implements ICustomFormatter, IFormatProvider

Private culture As CultureInfo

Public Sub New()
Me.New(CultureInfo.CurrentCulture)
End Sub

Public Sub New(culture As CultureInfo)
Me.culture = culture
End Sub

Public Function GetFormat(formatType As Type) As Object _
Implements IFormatProvider.GetFormat
If formatType Is GetType(ICustomFormatter) Then
Return Me
Else
Return Nothing
End If
End Function

Public Function Format(fmt As String, arg As Object,
formatProvider As IFormatProvider) As String _
Implements ICustomFormatter.Format
' Exit if another format provider is used.
If Not formatProvider.Equals(Me) Then Return Nothing

' Exit if the type to be formatted is not a Boolean
If Not TypeOf arg Is Boolean Then Return Nothing

Dim value As Boolean = CBool(arg)
Select culture.Name
Case "en-US"
Return value.ToString()
Case "fr-FR"
If value Then
Return "vrai"
Else
Return "faux"
End If
Case "ru-RU"
If value Then
Return "верно"
Else
Return "неверно"
End If
Case Else
Return value.ToString()
End Select
End Function
End Class
' The example displays the following output:
'          Value for '': True
'          Value for 'en-US': True
'          Value for 'fr-FR': vrai
'          Value for 'ru-RU': верно
``````

（選擇性）您可以使用資源檔來定義特定文化特性的布林字串。Optionally, you can use resource files to define culture-specific Boolean strings.

### 從布林值轉換為和Converting to and from Boolean values

Boolean 結構會執行 IConvertible 介面。The Boolean structure implements the IConvertible interface. 因此，您可以使用 Convert 類別，在 .NET 中的 Boolean 值和任何其他基本型別之間執行轉換，也可以呼叫 Boolean 結構的明確實值。As a result, you can use the Convert class to perform conversions between a Boolean value and any other primitive type in .NET, or you can call the Boolean structure's explicit implementations. 不過，不支援 Boolean 和下列類型之間的轉換，因此對應的轉換方法會擲回 InvalidCastException 例外狀況：However, conversions between a Boolean and the following types are not supported, so the corresponding conversion methods throw an InvalidCastException exception:

``````using System;

public class Example
{
public static void Main()
{
Byte byteValue = 12;
Console.WriteLine(Convert.ToBoolean(byteValue));
Byte byteValue2 = 0;
Console.WriteLine(Convert.ToBoolean(byteValue2));
int intValue = -16345;
Console.WriteLine(Convert.ToBoolean(intValue));
long longValue = 945;
Console.WriteLine(Convert.ToBoolean(longValue));
SByte sbyteValue = -12;
Console.WriteLine(Convert.ToBoolean(sbyteValue));
double dblValue = 0;
Console.WriteLine(Convert.ToBoolean(dblValue));
float sngValue = .0001f;
Console.WriteLine(Convert.ToBoolean(sngValue));
}
}
// The example displays the following output:
//       True
//       False
//       True
//       True
//       True
//       False
//       True
``````
``````Module Example
Public Sub Main()
Dim byteValue As Byte = 12
Console.WriteLine(Convert.ToBoolean(byteValue))
Dim byteValue2 As Byte = 0
Console.WriteLine(Convert.ToBoolean(byteValue2))
Dim intValue As Integer = -16345
Console.WriteLine(Convert.ToBoolean(intValue))
Dim longValue As Long = 945
Console.WriteLine(Convert.ToBoolean(longValue))
Dim sbyteValue As SByte = -12
Console.WriteLine(Convert.ToBoolean(sbyteValue))
Dim dblValue As Double = 0
Console.WriteLine(Convert.ToBoolean(dblValue))
Dim sngValue As Single = .0001
Console.WriteLine(Convert.ToBoolean(sngValue))
End Sub
End Module
' The example displays the following output:
'       True
'       False
'       True
'       True
'       True
'       False
'       True
``````

``````using System;

public class Example
{
public static void Main()
{
bool flag = true;

byte byteValue;
byteValue = Convert.ToByte(flag);
Console.WriteLine("{0} -> {1}", flag, byteValue);

sbyte sbyteValue;
sbyteValue = Convert.ToSByte(flag);
Console.WriteLine("{0} -> {1}", flag, sbyteValue);

double dblValue;
dblValue = Convert.ToDouble(flag);
Console.WriteLine("{0} -> {1}", flag, dblValue);

int intValue;
intValue = Convert.ToInt32(flag);
Console.WriteLine("{0} -> {1}", flag, intValue);
}
}
// The example displays the following output:
//       True -> 1
//       True -> 1
//       True -> 1
//       True -> 1
``````
``````Module Example
Public Sub Main()
Dim flag As Boolean = true

Dim byteValue As Byte
byteValue = Convert.ToByte(flag)
Console.WriteLine("{0} -> {1} ({2})", flag, byteValue,
byteValue.GetType().Name)
byteValue = CByte(flag)
Console.WriteLine("{0} -> {1} ({2})", flag, byteValue,
byteValue.GetType().Name)

Dim sbyteValue As SByte
sbyteValue = Convert.ToSByte(flag)
Console.WriteLine("{0} -> {1} ({2})", flag, sbyteValue,
sbyteValue.GetType().Name)
sbyteValue = CSByte(flag)
Console.WriteLine("{0} -> {1} ({2})", flag, sbyteValue,
sbyteValue.GetType().Name)

Dim dblValue As Double
dblValue = Convert.ToDouble(flag)
Console.WriteLine("{0} -> {1} ({2})", flag, dblValue,
dblValue.GetType().Name)
dblValue = CDbl(flag)
Console.WriteLine("{0} -> {1} ({2})", flag, dblValue,
dblValue.GetType().Name)

Dim intValue As Integer
intValue = Convert.ToInt32(flag)
Console.WriteLine("{0} -> {1} ({2})", flag, intValue,
intValue.GetType().Name)
intValue = CInt(flag)
Console.WriteLine("{0} -> {1} ({2})", flag, intValue,
intValue.GetType().Name)
End Sub
End Module
' The example displays the following output:
'       True -> 1 (Byte)
'       True -> 255 (Byte)
'       True -> 1 (SByte)
'       True -> -1 (SByte)
'       True -> 1 (Double)
'       True -> -1 (Double)
'       True -> 1 (Int32)
'       True -> -1 (Int32)
``````

### 剖析布林值Parsing Boolean values

Boolean 結構包含兩個靜態剖析方法，ParseTryParse，會將字串轉換成布林值。The Boolean structure includes two static parsing methods, Parse and TryParse, that convert a string to a Boolean value. 布林值的字串表示是由 TrueStringFalseString 欄位（分別為 "True" 和 "False"）的值不區分大小寫對等專案所定義。The string representation of a Boolean value is defined by the case-insensitive equivalents of the values of the TrueString and FalseString fields, which are "True" and "False", respectively. 換句話說，剖析成功的唯一字串是 "True"、"False"、"True"、"false" 或一些混合大小寫的對應。In other words, the only strings that parse successfully are "True", "False", "true", "false", or some mixed-case equivalent. 您無法成功剖析數值字串，例如 "0" 或 "1"。You cannot successfully parse numeric strings such as "0" or "1". 執行字串比較時，不會考慮前置或尾端空白字元。Leading or trailing white-space characters are not considered when performing the string comparison.

``````using System;

public class Example
{
public static void Main()
{
string[] values = { null, String.Empty, "True", "False",
"true", "false", "    true    ",
"TrUe", "fAlSe", "fa lse", "0",
"1", "-1", "string" };
// Parse strings using the Boolean.Parse method.
foreach (var value in values) {
try {
bool flag = Boolean.Parse(value);
Console.WriteLine("'{0}' --> {1}", value, flag);
}
catch (ArgumentException) {
Console.WriteLine("Cannot parse a null string.");
}
catch (FormatException) {
Console.WriteLine("Cannot parse '{0}'.", value);
}
}
Console.WriteLine();
// Parse strings using the Boolean.TryParse method.
foreach (var value in values) {
bool flag = false;
if (Boolean.TryParse(value, out flag))
Console.WriteLine("'{0}' --> {1}", value, flag);
else
Console.WriteLine("Unable to parse '{0}'", value);
}
}
}
// The example displays the following output:
//       Cannot parse a null string.
//       Cannot parse ''.
//       'True' --> True
//       'False' --> False
//       'true' --> True
//       'false' --> False
//       '    true    ' --> True
//       'TrUe' --> True
//       'fAlSe' --> False
//       Cannot parse 'fa lse'.
//       Cannot parse '0'.
//       Cannot parse '1'.
//       Cannot parse '-1'.
//       Cannot parse 'string'.
//
//       Unable to parse ''
//       Unable to parse ''
//       'True' --> True
//       'False' --> False
//       'true' --> True
//       'false' --> False
//       '    true    ' --> True
//       'TrUe' --> True
//       'fAlSe' --> False
//       Cannot parse 'fa lse'.
//       Unable to parse '0'
//       Unable to parse '1'
//       Unable to parse '-1'
//       Unable to parse 'string'
``````
``````Module Example
Public Sub Main()
Dim values() As String = { Nothing, String.Empty, "True", "False",
"true", "false", "    true    ",
"TrUe", "fAlSe", "fa lse", "0",
"1", "-1", "string" }
' Parse strings using the Boolean.Parse method.
For Each value In values
Try
Dim flag As Boolean = Boolean.Parse(value)
Console.WriteLine("'{0}' --> {1}", value, flag)
Catch e As ArgumentException
Console.WriteLine("Cannot parse a null string.")
Catch e As FormatException
Console.WriteLine("Cannot parse '{0}'.", value)
End Try
Next
Console.WriteLine()
' Parse strings using the Boolean.TryParse method.
For Each value In values
Dim flag As Boolean = False
If Boolean.TryParse(value, flag)
Console.WriteLine("'{0}' --> {1}", value, flag)
Else
Console.WriteLine("Cannot parse '{0}'.", value)
End If
Next
End Sub
End Module
' The example displays the following output:
'       Cannot parse a null string.
'       Cannot parse ''.
'       'True' --> True
'       'False' --> False
'       'true' --> True
'       'false' --> False
'       '    true    ' --> True
'       'TrUe' --> True
'       'fAlSe' --> False
'       Cannot parse 'fa lse'.
'       Cannot parse '0'.
'       Cannot parse '1'.
'       Cannot parse '-1'.
'       Cannot parse 'string'.
'
'       Unable to parse ''
'       Unable to parse ''
'       'True' --> True
'       'False' --> False
'       'true' --> True
'       'false' --> False
'       '    true    ' --> True
'       'TrUe' --> True
'       'fAlSe' --> False
'       Cannot parse 'fa lse'.
'       Unable to parse '0'
'       Unable to parse '1'
'       Unable to parse '-1'
'       Unable to parse 'string'
``````

``````using System;

public class Example
{
public static void Main()
{
String[] values = { "09", "12.6", "0", "-13 " };
foreach (var value in values) {
bool success, result;
int number;
success = Int32.TryParse(value, out number);
if (success) {
// The method throws no exceptions.
result = Convert.ToBoolean(number);
Console.WriteLine("Converted '{0}' to {1}", value, result);
}
else {
Console.WriteLine("Unable to convert '{0}'", value);
}
}
}
}
// The example displays the following output:
//       Converted '09' to True
//       Unable to convert '12.6'
//       Converted '0' to False
//       Converted '-13 ' to True
``````
``````Module Example
Public Sub Main()
Dim values() As String = { "09", "12.6", "0", "-13 " }
For Each value In values
Dim success, result As Boolean
Dim number As Integer
success = Int32.TryParse(value, number)
If success Then
' The method throws no exceptions.
result = Convert.ToBoolean(number)
Console.WriteLine("Converted '{0}' to {1}", value, result)
Else
Console.WriteLine("Unable to convert '{0}'", value)
End If
Next
End Sub
End Module
' The example displays the following output:
'       Converted '09' to True
'       Unable to convert '12.6'
'       Converted '0' to False
'       Converted '-13 ' to True
``````

### 比較布林值Comparing Boolean values

``````if (booleanValue) {
``````
``````If booleanValue Then
``````

and

``````using System;

public class Example
{
public static void Main()
{
bool[] hasServiceCharges = { true, false };
Decimal subtotal = 120.62m;
Decimal shippingCharge = 2.50m;
Decimal serviceCharge = 5.00m;

foreach (var hasServiceCharge in hasServiceCharges) {
Decimal total = subtotal + shippingCharge +
(hasServiceCharge ? serviceCharge : 0);
Console.WriteLine("hasServiceCharge = {1}: The total is {0:C2}.",
total, hasServiceCharge);
}
}
}
// The example displays output like the following:
//       hasServiceCharge = True: The total is \$128.12.
//       hasServiceCharge = False: The total is \$123.12.
``````
``````Module Example
Public Sub Main()
Dim hasServiceCharges() As Boolean = { True, False }
Dim subtotal As Decimal = 120.62d
Dim shippingCharge As Decimal = 2.50d
Dim serviceCharge As Decimal = 5.00d

For Each hasServiceCharge In hasServiceCharges
Dim total As Decimal = subtotal + shippingCharge +
If(hasServiceCharge, serviceCharge, 0)
Console.WriteLine("hasServiceCharge = {1}: The total is {0:C2}.",
total, hasServiceCharge)
Next
End Sub
End Module
' The example displays output like the following:
'       hasServiceCharge = True: The total is \$128.12.
'       hasServiceCharge = False: The total is \$123.12.
``````

### 使用布林值做為二進位值Working with Booleans as binary values

``````using System;

public struct BoolStruct
{
public bool flag1;
public bool flag2;
public bool flag3;
public bool flag4;
public bool flag5;
}

public class Example
{
public static void Main()
{
unsafe {
BoolStruct b = new BoolStruct();
bool* addr = (bool*) &b;
Console.WriteLine("Size of BoolStruct: {0}", sizeof(BoolStruct));
Console.WriteLine("Field offsets:");
Console.WriteLine("   flag1: {0}", (bool*) &b.flag1 - addr);
Console.WriteLine("   flag1: {0}", (bool*) &b.flag2 - addr);
Console.WriteLine("   flag1: {0}", (bool*) &b.flag3 - addr);
Console.WriteLine("   flag1: {0}", (bool*) &b.flag4 - addr);
Console.WriteLine("   flag1: {0}", (bool*) &b.flag5 - addr);
}
}
}
// The example displays the following output:
//       Size of BoolStruct: 5
//       Field offsets:
//          flag1: 0
//          flag1: 1
//          flag1: 2
//          flag1: 3
//          flag1: 4
``````

``````using System;

public class Example
{
public static void Main()
{
bool[] flags = { true, false };
foreach (var flag in flags) {
// Get binary representation of flag.
Byte value = BitConverter.GetBytes(flag)[0];
Console.WriteLine("Original value: {0}", flag);
Console.WriteLine("Binary value:   {0} ({1})", value,
GetBinaryString(value));
// Restore the flag from its binary representation.
bool newFlag = BitConverter.ToBoolean( new Byte[] { value }, 0);
Console.WriteLine("Restored value: {0}\n", flag);
}
}

private static string GetBinaryString(Byte value)
{
String retVal = Convert.ToString(value, 2);
return new String('0', 8 - retVal.Length) + retVal;
}
}
// The example displays the following output:
//       Original value: True
//       Binary value:   1 (00000001)
//       Restored value: True
//
//       Original value: False
//       Binary value:   0 (00000000)
//       Restored value: False
``````
``````Module Example
Public Sub Main()
Dim flags() As Boolean = { True, False }
For Each flag In flags
' Get binary representation of flag.
Dim value As Byte = BitConverter.GetBytes(flag)(0)
Console.WriteLine("Original value: {0}", flag)
Console.WriteLine("Binary value:   {0} ({1})", value,
GetBinaryString(value))
' Restore the flag from its binary representation.
Dim newFlag As Boolean = BitConverter.ToBoolean( { value }, 0)
Console.WriteLine("Restored value: {0}", flag)
Console.WriteLine()
Next
End Sub

Private Function GetBinaryString(value As Byte) As String
Dim retVal As String = Convert.ToString(value, 2)
Return New String("0"c, 8 - retVal.Length) + retVal
End Function
End Module
' The example displays the following output:
'       Original value: True
'       Binary value:   1 (00000001)
'       Restored value: True
'
'       Original value: False
'       Binary value:   0 (00000000)
'       Restored value: False
``````

### 使用布林值執行運算Performing operations with Boolean values

#### 布林值做為旗標Boolean values as flags

``````using System;
using System.IO;
using System.Threading;

public class Example
{
public static void Main()
{
// Initialize flag variables.
bool isRedirected = false;
bool isBoth = false;
String fileName = "";
StreamWriter sw = null;

// Get any command line arguments.
String[] args = Environment.GetCommandLineArgs();
// Handle any arguments.
if (args.Length > 1) {
for (int ctr = 1; ctr < args.Length; ctr++) {
String arg = args[ctr];
if (arg.StartsWith("/") || arg.StartsWith("-")) {
switch (arg.Substring(1).ToLower())
{
case "f":
isRedirected = true;
if (args.Length < ctr + 2) {
ShowSyntax("The /f switch must be followed by a filename.");
return;
}
fileName = args[ctr + 1];
ctr++;
break;
case "b":
isBoth = true;
break;
default:
ShowSyntax(String.Format("The {0} switch is not supported",
args[ctr]));
return;
}
}
}
}

// If isBoth is True, isRedirected must be True.
if (isBoth &&  ! isRedirected) {
ShowSyntax("The /f switch must be used if /b is used.");
return;
}

// Handle output.
if (isRedirected) {
sw = new StreamWriter(fileName);
if (!isBoth)
Console.SetOut(sw);
}
String msg = String.Format("Application began at {0}", DateTime.Now);
Console.WriteLine(msg);
if (isBoth) sw.WriteLine(msg);
Thread.Sleep(5000);
msg = String.Format("Application ended normally at {0}", DateTime.Now);
Console.WriteLine(msg);
if (isBoth) sw.WriteLine(msg);
if (isRedirected) sw.Close();
}

private static void ShowSyntax(String errMsg)
{
Console.WriteLine(errMsg);
Console.WriteLine("\nSyntax: Example [[/f <filename> [/b]]\n");
}
}
``````
``````Imports System.IO
Imports System.Threading

Module Example
Public Sub Main()
' Initialize flag variables.
Dim isRedirected, isBoth As Boolean
Dim fileName As String = ""
Dim sw As StreamWriter = Nothing

' Get any command line arguments.
Dim args() As String = Environment.GetCommandLineArgs()
' Handle any arguments.
If args.Length > 1 Then
For ctr = 1 To args.Length - 1
Dim arg As String = args(ctr)
If arg.StartsWith("/") OrElse arg.StartsWith("-") Then
Select Case arg.Substring(1).ToLower()
Case "f"
isRedirected = True
If args.Length < ctr + 2 Then
ShowSyntax("The /f switch must be followed by a filename.")
Exit Sub
End If
fileName = args(ctr + 1)
ctr += 1
Case "b"
isBoth = True
Case Else
ShowSyntax(String.Format("The {0} switch is not supported",
args(ctr)))
Exit Sub
End Select
End If
Next
End If

' If isBoth is True, isRedirected must be True.
If isBoth And Not isRedirected Then
ShowSyntax("The /f switch must be used if /b is used.")
Exit Sub
End If

' Handle output.
If isRedirected Then
sw = New StreamWriter(fileName)
If Not IsBoth Then
Console.SetOut(sw)
End If
End If
Dim msg As String = String.Format("Application began at {0}", Date.Now)
Console.WriteLine(msg)
If isBoth Then sw.WriteLine(msg)
Thread.Sleep(5000)
msg = String.Format("Application ended normally at {0}", Date.Now)
Console.WriteLine(msg)
If isBoth Then sw.WriteLine(msg)
If isRedirected Then sw.Close()
End Sub

Private Sub ShowSyntax(errMsg As String)
Console.WriteLine(errMsg)
Console.WriteLine()
Console.WriteLine("Syntax: Example [[/f <filename> [/b]]")
Console.WriteLine()
End Sub
End Module
``````

#### 布林值和算數運算Booleans and arithmetic operations

``````using System;

public class Example
{
public static void Main()
{
bool[] hasServiceCharges = { true, false };
Decimal subtotal = 120.62m;
Decimal shippingCharge = 2.50m;
Decimal serviceCharge = 5.00m;

foreach (var hasServiceCharge in hasServiceCharges) {
Decimal total = subtotal + shippingCharge +
(hasServiceCharge ? serviceCharge : 0);
Console.WriteLine("hasServiceCharge = {1}: The total is {0:C2}.",
total, hasServiceCharge);
}
}
}
// The example displays output like the following:
//       hasServiceCharge = True: The total is \$128.12.
//       hasServiceCharge = False: The total is \$123.12.
``````
``````Module Example
Public Sub Main()
Dim hasServiceCharges() As Boolean = { True, False }
Dim subtotal As Decimal = 120.62d
Dim shippingCharge As Decimal = 2.50d
Dim serviceCharge As Decimal = 5.00d

For Each hasServiceCharge In hasServiceCharges
Dim total As Decimal = subtotal + shippingCharge +
If(hasServiceCharge, serviceCharge, 0)
Console.WriteLine("hasServiceCharge = {1}: The total is {0:C2}.",
total, hasServiceCharge)
Next
End Sub
End Module
' The example displays output like the following:
'       hasServiceCharge = True: The total is \$128.12.
'       hasServiceCharge = False: The total is \$123.12.
``````

#### 布林值和 interopBooleans and interop

UnmanagedType.Bool 4個位元組的整數值，其中任何非零值表示 `true`，而0代表 `false`A 4-byte integer value, where any nonzero value represents `true` and 0 represents `false`. 這是在平台叫用呼叫的結構和 Boolean 參數中，Boolean 欄位的預設格式。This is the default format of a Boolean field in a structure and of a Boolean parameter in platform invoke calls.
UnmanagedType.U1 1個位元組的整數值，其中1代表 `true`，而0代表 `false`A 1-byte integer value, where the 1 represents `true` and 0 represents `false`.
UnmanagedType.VariantBool 2個位元組的整數值，其中-1 代表 `true`，而0代表 `false`A 2-byte integer value, where -1 represents `true` and 0 represents `false`. 這是 COM Interop 呼叫中 Boolean 參數的預設格式。This is the default format of a Boolean parameter in COM interop calls.

## 欄位

 將布林值 `false` 表示為字串。Represents the Boolean value `false` as a string. 此欄位為唯讀。This field is read-only. 將布林值 `true` 表示為字串。Represents the Boolean value `true` as a string. 此欄位為唯讀。This field is read-only.

## 方法

 比較這個執行個體與指定的 Boolean 物件，並傳回整數，這個整數表示兩者彼此的關聯性。Compares this instance to a specified Boolean object and returns an integer that indicates their relationship to one another. 將這個執行個體與指定的物件相比較，並傳回整數，這個整數表示兩者彼此的關聯性 (Relationship)。Compares this instance to a specified object and returns an integer that indicates their relationship to one another. 傳回表示這個執行個體是否等於指定 Boolean 物件的值。Returns a value indicating whether this instance is equal to a specified Boolean object. 傳回值，指出此執行個體是否等於指定的物件。Returns a value indicating whether this instance is equal to a specified object. 傳回此執行個體的雜湊碼。Returns the hash code for this instance. 傳回 Boolean 實值類型的類型程式碼。Returns the type code for the Boolean value type. 將代表邏輯值的指定範圍轉換為其對等 Boolean。Converts the specified span representation of a logical value to its Boolean equivalent. 將指定之邏輯值的字串表示，轉換為相等的 Boolean。Converts the specified string representation of a logical value to its Boolean equivalent. 將這個執行個體的值轉換為它的對等字串表示 ("True" 或 "False")。Converts the value of this instance to its equivalent string representation (either "True" or "False"). 將這個執行個體的值轉換為它的對等字串表示 ("True" 或 "False")。Converts the value of this instance to its equivalent string representation (either "True" or "False"). 嘗試將目前布林執行個體的值格式化為所提供字元範圍。Tries to format the value of the current boolean instance into the provided span of characters. 嘗試將代表邏輯值的指定範圍轉換為對等 Boolean。Tries to convert the specified span representation of a logical value to its Boolean equivalent. 嘗試將指定之邏輯值的字串表示轉換成對等的 Boolean。Tries to convert the specified string representation of a logical value to its Boolean equivalent.

## 明確介面實作

 如需這個成員的說明，請參閱 ToBoolean(IFormatProvider)。For a description of this member, see ToBoolean(IFormatProvider). 如需這個成員的說明，請參閱 ToByte(IFormatProvider)。For a description of this member, see ToByte(IFormatProvider). 不支援這個轉換。This conversion is not supported. 嘗試使用這個方法會擲回 InvalidCastException。Attempting to use this method throws an InvalidCastException. 不支援這個轉換。This conversion is not supported. 嘗試使用這個方法會擲回 InvalidCastException。Attempting to use this method throws an InvalidCastException. 如需這個成員的說明，請參閱 ToDecimal(IFormatProvider)。For a description of this member, see ToDecimal(IFormatProvider). 如需這個成員的說明，請參閱 ToDouble(IFormatProvider)。For a description of this member, see ToDouble(IFormatProvider). 如需這個成員的說明，請參閱 ToInt16(IFormatProvider)。For a description of this member, see ToInt16(IFormatProvider). 如需這個成員的說明，請參閱 ToInt32(IFormatProvider)。For a description of this member, see ToInt32(IFormatProvider). 如需這個成員的說明，請參閱 ToInt64(IFormatProvider)。For a description of this member, see ToInt64(IFormatProvider). 如需這個成員的說明，請參閱 ToSByte(IFormatProvider)。For a description of this member, see ToSByte(IFormatProvider). 如需這個成員的說明，請參閱 ToSingle(IFormatProvider)。For a description of this member, see ToSingle(IFormatProvider). 如需這個成員的說明，請參閱 ToType(Type, IFormatProvider)。For a description of this member, see ToType(Type, IFormatProvider). 如需這個成員的說明，請參閱 ToUInt16(IFormatProvider)。For a description of this member, see ToUInt16(IFormatProvider). 如需這個成員的說明，請參閱 ToUInt32(IFormatProvider)。For a description of this member, see ToUInt32(IFormatProvider). 如需這個成員的說明，請參閱 ToUInt64(IFormatProvider)。For a description of this member, see ToUInt64(IFormatProvider).