返回到原始开始位置，而无需退出应用程序并再次打开它

Question

purpose of the app really simple. Ask the user to enter a number and checks if the user number and randomly created number are the same. Until the user enters the correct number it goes on. Once the user enters correct number how can i change my random number so they can continue without quitting the application.Right now i have to quit once i find the correct number.And open it back again.
public class MainActivity extends AppCompatActivity { int number; //Global Variabble.

    public void clicked (View view ){
       EditText userinput = (EditText)findViewById(R.id.userinput);
       String inputstring = userinput.getText().toString();
       if (inputstring == " "){
          Toast.makeText(getApplicationContext(),"You havent entered anything",Toast.LENGTH_SHORT).show();
    }

    int inputint = Integer.parseInt(inputstring);

    if (inputint > number ){
        Toast.makeText(getApplicationContext(),"No, too high",Toast.LENGTH_SHORT).show();
    }
    else if (inputint < number){
        Toast.makeText(getApplicationContext(),"No, too small",Toast.LENGTH_SHORT).show();
    }
    else{
        Toast.makeText(getApplicationContext(),"Well Done! You Guessed it",Toast.LENGTH_SHORT).show();

    }

        //System.out.println("Computer guessed number is: " + number);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
    Random r = new Random();
    number = r.nextInt(21);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

}

Answer 1

you can try random function like this

public void randomGenerator()
{
  Random r = new random
  number = r.nextInt(21) //put the int number creation in global
}

then call it at onCreate()

    @Override
protected void onCreate(Bundle savedInstanceState) {

    randomGenerator()
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

also at the else statement

else{
        Toast.makeText(getApplicationContext(),"Well Done! You Guessed it",Toast.LENGTH_SHORT).show();

        randomGenerator(); //random number after user get correct answer

    }

Answer 2

you can put

Random r = new Random(); number = r.nextInt(21); userinput.setText("");

in a function, and call it when your intent is call for the first time (in the on create) and cal it again when the use has found the good number