TextInfo.ToTitleCase(String) 方法

定义

命名空间:

System.Globalization

程序集:

System.Runtime.dll

程序集:

netstandard.dll

程序集:

mscorlib.dll

将指定字符串转换为词首字母大写（不包含视为首字母缩写的全部大写词）。

public:
 System::String ^ ToTitleCase(System::String ^ str);

public string ToTitleCase (string str);

member this.ToTitleCase : string -> string

Public Function ToTitleCase (str As String) As String

参数

str

String

转换为标题大写的字符串。

返回

String

转换为标题大写的指定字符串。

例外

ArgumentNullException

str 为 null。

示例

下面的示例基于英语（美国）区域性（区域性名称为 en-US）更改字符串的大小写。

using namespace System;
using namespace System::Globalization;
int main()
{
   
   // Defines the String* with mixed casing.
   String^ myString = "wAr aNd pEaCe";
   
   // Creates a TextInfo based on the S"en-US" culture.
   CultureInfo^ MyCI = gcnew CultureInfo( "en-US",false );
   TextInfo^ myTI = MyCI->TextInfo;
   
   // Changes a String* to lowercase.
   Console::WriteLine( "\"{0}\" to lowercase: {1}", myString, myTI->ToLower( myString ) );
   
   // Changes a String* to uppercase.
   Console::WriteLine( "\"{0}\" to uppercase: {1}", myString, myTI->ToUpper( myString ) );
   
   // Changes a String* to titlecase.
   Console::WriteLine( "\"{0}\" to titlecase: {1}", myString, myTI->ToTitleCase( myString ) );
}

/*
This code produces the following output.

S"wAr aNd pEaCe" to lowercase: war and peace
S"wAr aNd pEaCe" to uppercase: WAR AND PEACE
S"wAr aNd pEaCe" to titlecase: War And Peace

*/

using System;
using System.Globalization;

public class SamplesTextInfo  {

   public static void Main()  {

      // Defines the string with mixed casing.
      string myString = "wAr aNd pEaCe";

      // Creates a TextInfo based on the "en-US" culture.
      TextInfo myTI = new CultureInfo("en-US",false).TextInfo;

      // Changes a string to lowercase.
      Console.WriteLine( "\"{0}\" to lowercase: {1}", myString, myTI.ToLower( myString ) );

      // Changes a string to uppercase.
      Console.WriteLine( "\"{0}\" to uppercase: {1}", myString, myTI.ToUpper( myString ) );

      // Changes a string to titlecase.
      Console.WriteLine( "\"{0}\" to titlecase: {1}", myString, myTI.ToTitleCase( myString ) );
   }
}

/*
This code produces the following output.

"wAr aNd pEaCe" to lowercase: war and peace
"wAr aNd pEaCe" to uppercase: WAR AND PEACE
"wAr aNd pEaCe" to titlecase: War And Peace

*/

Imports System.Globalization

Public Class SamplesTextInfo

   Public Shared Sub Main()

      ' Defines the string with mixed casing.
      Dim myString As String = "wAr aNd pEaCe"

      ' Creates a TextInfo based on the "en-US" culture.
      Dim myTI As TextInfo = New CultureInfo("en-US", False).TextInfo

      ' Changes a string to lowercase.
      Console.WriteLine("""{0}"" to lowercase: {1}", myString, myTI.ToLower(myString))

      ' Changes a string to uppercase.
      Console.WriteLine("""{0}"" to uppercase: {1}", myString, myTI.ToUpper(myString))

      ' Changes a string to titlecase.
      Console.WriteLine("""{0}"" to titlecase: {1}", myString, myTI.ToTitleCase(myString))

   End Sub

End Class


'This code produces the following output.
'
'"wAr aNd pEaCe" to lowercase: war and peace
'"wAr aNd pEaCe" to uppercase: WAR AND PEACE
'"wAr aNd pEaCe" to titlecase: War And Peace

下面的示例将数组中的每个字符串传递至 ToTitleCase 方法。 字符串包含适当的标题字符串以及首字母缩写词。 通过使用 en-US 区域性的约定将字符串转换为标题大小写。

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      string[] values = { "a tale of two cities", "gROWL to the rescue",
                          "inside the US government", "sports and MLB baseball",
                          "The Return of Sherlock Holmes", "UNICEF and children"};

      TextInfo ti = CultureInfo.CurrentCulture.TextInfo;
      foreach (var value in values)
         Console.WriteLine("{0} --> {1}", value, ti.ToTitleCase(value));
   }
}
// The example displays the following output:
//    a tale of two cities --> A Tale Of Two Cities
//    gROWL to the rescue --> Growl To The Rescue
//    inside the US government --> Inside The US Government
//    sports and MLB baseball --> Sports And MLB Baseball
//    The Return of Sherlock Holmes --> The Return Of Sherlock Holmes
//    UNICEF and children --> UNICEF And Children

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim values() As String = { "a tale of two cities", "gROWL to the rescue",
                                 "inside the US government", "sports and MLB baseball",
                                 "The Return of Sherlock Holmes", "UNICEF and children"}
                                 
      Dim ti As TextInfo = CultureInfo.CurrentCulture.TextInfo
      For Each value In values
         Console.WriteLine("{0} --> {1}", value, ti.ToTitleCase(value))
      Next
   End Sub
End Module
' The example displays the following output:
'    a tale of two cities --> A Tale Of Two Cities
'    gROWL to the rescue --> Growl To The Rescue
'    inside the US government --> Inside The US Government
'    sports and MLB baseball --> Sports And MLB Baseball
'    The Return of Sherlock Holmes --> The Return Of Sherlock Holmes
'    UNICEF and children --> UNICEF And Children

注解

通常，标题大小写将单词的第一个字符转换为大写，将其余字符转换为小写。 但是，此方法当前不提供正确的大小写来转换完全大写的单词，例如首字母缩略词。 下表显示了 方法呈现多个字符串的方式。

输入	语言	预期结果	实际结果
war and war and war	英语	War and Peace	War And Peace
Per anhalter durch die Galaxis	德语	Per Anhalter durch die Galaxis	Per Anhalter Durch Die Galaxis
les naufragés d'ythaq	法语	Les Naufragés d'Ythaq	Les Naufragés D'ythaq

如上所示， 方法提供了任意大小写行为，该行为在语言上 ToTitleCase 不一定正确。 语言正确的解决方案需要额外的规则，并且当前算法稍微简单一些且速度更快。 我们保留将来使此 API 速度变慢的权利。

方法的当前实现生成与输入字符串长度相同的 ToTitleCase 输出字符串。 但是，此行为不保证，并且在将来的实现中可能会更改。

另请参阅

• ToLower(Char)
• ToUpper(Char)