HOWTO: 判斷全形和半形

ASCII碼大於255，則為雙位元組？

另外查看MSDN中KeyPress事件

1,FCL

System.Text.UnicodeEncoding.Unicode.GetByteCoun(str)

實驗無效。全部返回2，又實驗ASCIIEncoding.ASCII類的同名方法，全部返回1

2,Regex

全形：[^\x00-\xff]

3,第三方實現

   1:  #region 半全形互換

   2:  /// <summary>

   3:  /// 轉全形的函數(SBC case)

   4:  /// </summary>

   5:  /// <param name="input">任一字元串</param>

   6:  /// <returns>全形字元串</returns>

   7:  ///<remarks>

   8:  ///全形空格為12288，半形空格為32

9: ///其他字元半形(33-126)與全形(65281-65374)的對應關係是：均相差65248

  10:  ///</remarks>        

  11:  public static string ToSBC(string input)

  12:  {

  13:      //半形轉全形：

  14:      char[] c = input.ToCharArray();

  15:      for (int i = 0; i < c.Length; i++)

  16:      {

  17:          if (c[i] == 32)

  18:          {

  19:              c[i] = (char)12288;

  20:              continue;

  21:          }

  22:          if (c[i] < 127 && c[i] > 32)

  23:          {

  24:              c[i] = (char)(c[i] + 65248);

  25:          }

  26:      }

  27:      return new string(c);

  28:  }

  29:   

  30:  /// <summary>

  31:  /// 轉半形的函數(DBC case)

  32:  /// </summary>

  33:  /// <param name="input">任一字元串</param>

  34:  /// <returns>半形字元串</returns>

  35:  ///<remarks>

  36:  ///全形空格為12288，半形空格為32(此處不必轉空格)

37: ///其他字元半形(33-126)與全形(65281-65374)的對應關係是：均相差65248

  38:  ///</remarks>

  39:  public static string ToDBC(string input)

  40:  {

  41:      char[] c = input.ToCharArray();

  42:      for (int i = 0; i < c.Length; i++)

  43:      {

  44:          if (c[i] == 12288)

  45:          {

  46:              c[i] = (char)32;

  47:              continue;

  48:          }

  49:          if (c[i] > 65280 && c[i] < 65375)

  50:          {

  51:              c[i] = (char)(c[i] - 65248);

  52:          }

  53:      }

  54:      return new string(c);

  55:  }

  56:  #endregion