//引入命名空间
using System;

public class CharStructureSample
{
    public static void Main()
    {
        char chA = 'A';
        char ch1 = '1';
        string str = "test string"; 

        Console.WriteLine(chA.CompareTo('B'));          //-----------  Output: "-1" (meaning 'A' is 1 less than 'B')
        Console.WriteLine(chA.Equals('A'));             //-----------  Output: "True"
        Console.WriteLine(Char.GetNumericValue(ch1));   //-----------  Output: "1"
        Console.WriteLine(Char.IsControl('\t'));        //-----------  Output: "True"
        Console.WriteLine(Char.IsDigit(ch1));           //-----------  Output: "True"
        Console.WriteLine(Char.IsLetter(','));          //-----------  Output: "False"
        Console.WriteLine(Char.IsLower('u'));           //-----------  Output: "True"
        Console.WriteLine(Char.IsNumber(ch1));          //-----------  Output: "True"
        Console.WriteLine(Char.IsPunctuation('.'));     //-----------  Output: "True"
        Console.WriteLine(Char.IsSeparator(str, 4));    //-----------  Output: "True"
        Console.WriteLine(Char.IsSymbol('+'));          //-----------  Output: "True"
        Console.WriteLine(Char.IsWhiteSpace(str, 4));   //-----------  Output: "True"
        Console.WriteLine(Char.Parse("S"));             //-----------  Output: "S"
        Console.WriteLine(Char.ToLower('M'));           //-----------  Output: "m"
        Console.WriteLine('x'.ToString());              //-----------  Output: "x"
    }
}

//引入命名空间
using System;
using System.IO;

public class Example
{
   public static void Main()
   {
      StreamWriter sw = new StreamWriter("chars1.txt");
      char[] chars = { '\u0061', '\u0308' };
      string strng = new String(chars);
      sw.WriteLine(strng); 
      sw.Close();
   }
}

//引入命名空间
using System;
using System.IO;

public class Example
{
   public static void Main()
   {
      StreamWriter sw = new StreamWriter(@".\chars2.txt");
      int utf32 = 0x1D160;
      string surrogate = Char.ConvertFromUtf32(utf32);
      sw.WriteLine("U+{0:X6} UTF-32 = {1} ({2}) UTF-16", 
                   utf32, surrogate, ShowCodePoints(surrogate));
      sw.Close();                    
   }

   private static string ShowCodePoints(string value)
   {
      string retval = null;
      foreach (var ch in value)
         retval += String.Format("U+{0:X4} ", Convert.ToUInt16(ch));

      return retval.Trim();
   }
}

//引入命名空间
using System;
using System.Globalization;

class Example
{
   public static void Main()
   {
      // Define a string with a variety of character categories.
      String s = "The red car drove down the long, narrow, secluded road.";
      // Determine the category of each character.
      foreach (var ch in s)
         Console.WriteLine("'{0}': {1}", ch, Char.GetUnicodeCategory(ch)); 
   }
}

//引入命名空间
using System;

public class Example
{
   public static void Main()
   {
      string result = String.Empty;
      for (int ctr = 0x10107; ctr <= 0x10110; ctr++)  // Range of Aegean numbers.
         result += Char.ConvertFromUtf32(ctr);

      Console.WriteLine("The string contains {0} characters.", result.Length); 
   }
}

//引入命名空间
using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      string result = String.Empty;
      for (int ctr = 0x10107; ctr <= 0x10110; ctr++)  // Range of Aegean numbers.
         result += Char.ConvertFromUtf32(ctr);

      StringInfo si = new StringInfo(result);
      Console.WriteLine("The string contains {0} characters.", 
                        si.LengthInTextElements); 
   }
}

//引入命名空间
using System;

public class Example
{
   public static void Main()
   {
      string combining = "\u0061\u0308";
      ShowString(combining);
      
      string normalized = combining.Normalize();
      ShowString(normalized);
   }

   private static void ShowString(string s)
   {
      Console.Write("Length of string: {0} (", s.Length);
      for (int ctr = 0; ctr < s.Length; ctr++) {
         Console.Write("U+{0:X4}", Convert.ToUInt16(s[ctr]));
         if (ctr != s.Length - 1) Console.Write(" ");
      } 
      Console.WriteLine(")\n");
   }
}