C#中，将Unicode 字符转换为ascii字符

using System;
using System.Text;

namespace ConvertExample
{
class ConvertExampleClass
{
static void Main()
{
string unicodeString = "This string contains the unicode character Pi(/u03a0)";

// Create two different encodings.
Encoding ascii = Encoding.ASCII;
Encoding unicode = Encoding.Unicode;

// Convert the string into a byte[].
byte[] unicodeBytes = unicode.GetBytes(unicodeString);

// Perform the conversion from one encoding to the other.
byte[] asciiBytes = Encoding.Convert(unicode, ascii, unicodeBytes);

// Convert the new byte[] into a char[] and then into a string.
// This is a slightly different approach to converting to illustrate
// the use of GetCharCount/GetChars.
char[] asciiChars = new char[ascii.GetCharCount(asciiBytes, 0, asciiBytes.Length)];
ascii.GetChars(asciiBytes, 0, asciiBytes.Length, asciiChars, 0);
string asciiString = new string(asciiChars);

// Display the strings created before and after the conversion.
Console.WriteLine("Original string: {0}", unicodeString);
Console.WriteLine("Ascii converted string: {0}", asciiString);
}
}
}