C#里面全角和半角的自由转换

半角转全角：
 c="hello World".ToCharArray();
        for (int i=0;i<c.Length;i++)
        {
            byte[] b=System.Text.Encoding.Unicode.GetBytes(c,i,1);
            if (b.Length= =2)
                  {
                   if (b[1]= =0)
                         {
                       b[0]=(byte)(b[0]-32);
                       b[1]=255;
                       c[i]=System.Text.Encoding.Unicode.GetChars(b)[0];
                         }
                  }
        }
string strNew=new string(c);

全角转半角：

string QJstr = "hello，Amigo  quanjiao字符";
  char[] c=QJstr.ToCharArray();
  for (int i=0;i<c.Length;i++)
  {
   byte[] b=System.Text.Encoding.Unicode.GetBytes(c,i,1);
   if (b.Length= =2)
   {
    if (b[1]= =255)
    {
     b[0]=(byte)(b[0]+32);
     b[1]=0;
     c[i]=System.Text.Encoding.Unicode.GetChars(b)[0];
    }
   }
  }
  string strNew=new string(c);