public static string DecryptStr( string rs ) //顺序减1解码
{
byte[] by=new byte[rs.Length];
for( int i=0;
i<=rs.Length-1;
i++ )
{
by[i]=( byte )( ( byte )rs[i]-1 );
}
rs="";
for( int i=by.Length-1;
i>=0;
i-- )
{
rs+=( ( char )by[i] ).ToString( );
}
return rs;
}

public static string EncryptStr( string rs ) //倒序加1加密
{
byte[] by=new byte[rs.Length];
for( int i=0;
i<=rs.Length-1;
i++ )
{
by[i]=( byte )( ( byte )rs[i]+1 );
}
rs="";
for( int i=by.Length-1;
i>=0;
i-- )
{
rs+=( ( char )by[i] ).ToString( );
}
return rs;
}