C # version Guess number

Using System;

Namespace Guessnumber
{
<summary>
Summary description of the CLASS1.
</summary>
Class Class1
{
<summary>
The main entry point for the application.
</summary>
[STAThread]
static void Main (string[] args)
{
Guessgame mygame=new guessgame ();
while (Mygame.play (). ToUpper () = = "Y")
{

}
}

}

Class Guessgame
{
private int resultnumber=1;
int usernumber=0;
int chance=0;
String Flag= "";
String Tempstr= "";

Public Guessgame ()
{
Init ();//
}

public string Play ()
{
Console.WriteLine ("Input A number:");
Tempstr=console.readline ();
while (! Isnum (TEMPSTR))
{
Tempstr=console.readline ();
}
Usernumber=convert.toint16 (TEMPSTR);
while (Resultnumber!=usernumber)
{
if (Resultnumber>usernumber)
Flag= "SAMLL";
Else
Flag= "Big";
Chance+=1;
Console.WriteLine ("Too {0}!!! You have guessed {1} times,input a number again: ", flag,chance);
Tempstr=console.readline ();
while (! Isnum (TEMPSTR))
{

}usernumber=convert.toint16 (TEMPSTR);
}
Console.Write ("You did it! {0} times ", chance+1);
Console.Write ("Play again?") Y:n ");
return Console.ReadLine ();
}

Private override string ReadLine ()
//  {
//
//  }

private void Init ()
{
Resultnumber = Createnumber ();
Console.WriteLine ("The number is between 1-100");
}

private int Createnumber ()
{
Random myran=new Random ();
Return Myran.next (0,10);
}

private bool Isnum (string Str)
{
for (int i=0;i<str.length;i++)
//   {
if (Convert.ToInt16 (str.substring (i,1)) <convert.toint16 ("0") | | Convert.ToInt16 (str.substring (i,1)) >convert.toint16 ("9"))
//    {
Console.WriteLine ("Fomat error,input a number");
return false;
//    }
//   }
Try
{
Convert.todouble (STR);
return true;
}
Catch
{
Console.WriteLine ("Fomat error,input a number");
return false;
}

}

}

}