1public class Class1
  2    {
  3        public StringBuilder keyWord;
  4        public char[] plaintext;
  5        public char[] key;
  6        public char[][] Vtable;
  7        private string p="abcdefghijklmnopqrstuvwxyz";
  8        public StringBuilder result;
  9        public string[] v=
 10        {
 11        "ABCDEFGHIJKLMNOPQRSTUVWXYZ","BCDEFGHIJKLMNOPQRSTUVWXYZA",
 12        "CDEFGHIJKLMNOPQRSTUVWXYZAB","DEFGHIJKLMNOPQRSTUVWXYZABC",
 13        "EFGHIJKLMNOPQRSTUVWXYZABCD","FGHIJKLMNOPQRSTUVWXYZABCDE",
 14        "GHIJKLMNOPQRSTUVWXYZABCDEF","HIJKLMNOPQRSTUVWXYZABCDEFG",
 15        "IJKLMNOPQRSTUVWXYZABCDEFGH","JKLMNOPQRSTUVWXYZABCDEFGHI",
 16        "KLMNOPQRSTUVWXYZABCDEFGHIJ","LMNOPQRSTUVWXYZABCDEFGHIJK",
 17        "MNOPQRSTUVWXYZABCDEFGHIJKL","NOPQRSTUVWXYZABCDEFGHIJKLM",
 18        "OPQRSTUVWXYZABCDEFGHIJKLMN","PQRSTUVWXYZABCDEFGHIJKLMNO",
 19        "QRSTUVWXYZABCDEFGHIJKLMNOP","RSTUVWXYZABCDEFGHIJKLMNOPQ",
 20        "STUVWXYZABCDEFGHIJKLMNOPQR","TUVWXYZABCDEFGHIJKLMNOPQRS",
 21        "UVWXYZABCDEFGHIJKLMNOPQRST","VWXYZABCDEFGHIJKLMNOPQRSTU",
 22        "WXYZABCDEFGHIJKLMNOPQRSTUV","XYZABCDEFGHIJKLMNOPQRSTUVW",
 23        "YZABCDEFGHIJKLMNOPQRSTUVWX","ZABCDEFGHIJKLMNOPQRSTUVWXY"};
 24
 25        public Class1()
 26        {
 27            keyWord=new StringBuilder();
 28            plaintext=new char[100];
 29            key=new char[100];
 30            Vtable=new char[26][];
 31            result=new StringBuilder();
 32            for(int i=0;i<v.Length;i++)
 33            { 
 34                Vtable[i]=v[i].ToCharArray();
 35            }
 36            
 37            //
 38            // TODO: 在此处添加构造函数逻辑
 39            //
 40        }
 41
 42        private void GetKey()
 43        {
 44            int Pnum,KWnum,n,ne;
 45            string k,k1,k2;
 46            k2=keyWord.ToString();
 47            Pnum=plaintext.Length;
 48            KWnum=keyWord.Length;
 49            if(Pnum>KWnum)
 50            {
 51                n=Pnum/KWnum;
 52                ne=Pnum%KWnum;
 53                for(int i=1;i<n;i++)
 54                    keyWord.Append(k2);
 55                k=keyWord.ToString().Substring(0,ne);
 56                keyWord.Append(k);
 57                k1=keyWord.ToString();
 58                key=keyWord.ToString().ToCharArray();
 59            }
 60            else
 61            {
 62                key=keyWord.ToString().Substring(0,Pnum).ToCharArray();
 63            }
 64                
 65        }
 66
 67        public void EncryptData(string str,string str2)//str为加密的明文，str2为密钥
 68        {
 69            int x,y;
 70            keyWord.Append(str2);
 71            plaintext=str.ToCharArray();
 72            GetKey();
 73            for(int i=0;i<key.Length;i++)
 74            {
 75                x=p.IndexOf(plaintext[i].ToString());
 76                y=p.IndexOf(key[i].ToString());
 77                result.Append(Vtable[x][y].ToString());
 78            }
 79            string fileName="c:\\Encryptdate.txt";
 80            if(File.Exists(fileName))
 81            {
 82                File.Delete(fileName);
 83            }
 84            FileStream fs = File.Create(fileName);
 85            
 86            StreamWriter sw=new StreamWriter(fs,System.Text.Encoding.Unicode);
 87            sw.Write(result);
 88            sw.Flush();
 89            fs.Close();
 90            keyWord.Remove(0,keyWord.Length);
 91            result.Remove(0,result.Length);
 92            
 93        }
 94
 95        public void GetPlainWord(string str,string str2)//str为解密的密文,str2为密钥
 96        {
 97            int x,y;
 98            keyWord.Append(str2);
 99            plaintext=str.ToCharArray();
100            GetKey();
101            for(int i=0;i<key.Length;i++)
102            {
103                y=p.IndexOf(key[i].ToString());
104                x=v[y].IndexOf(plaintext[i].ToString());
105                result.Append(p[x].ToString());
106            }
107            string fileName="c:\\plaintext.txt";
108            if(File.Exists(fileName))
109            {
110                File.Delete(fileName);
111            }
112            FileStream fs=File.Create(fileName);
113            StreamWriter sw=new StreamWriter(fs,System.Text.Encoding.Unicode);
114            sw.Write(result);
115            sw.Flush();
116            fs.Close();
117            keyWord.Remove(0,keyWord.Length);
118            result.Remove(0,result.Length);
119        }
120
121    }