C＃控制檯程序循環問題

Question

我試圖創建一個C＃程序，它爲用戶提供了3個選項：

1. 創建名稱（獲取用戶輸入他們的名字和姓氏，並顯示爲J.Blogg ）

2. 若干階乘（輸出作爲例如5x4x3x2x1 = 120，其爲5

3. 階乘退出

我有程序工作正常，但當我嘗試選擇選項1（創建名稱），然後選項2它轉到選項1，然後它不讓我退出（選項3）。 我是新來的編程，所以它可能很簡單，但我不明白我要去哪裏錯了， 任何幫助將是非常偉大的。 我想保持相同的佈局，我認爲我的問題可能是循環，但任何幫助和改進都會很好。

static void Main(string[] args) 
    { 

     //The value returned from the topmenu method is stored in a variable called useroption 
     int useroption; 
     useroption = topmenu(); 

     // excute while loop untill option is not 1-3 
     do 
     { 


      if (useroption == 1) 
      { 
       Console.Clear(); 
       Createname(); 
       //break; 
      } 

      if (useroption == 2) 
      { 
       Console.Clear(); 
       factorial(); 
       // break; 
      } 

      if (useroption == 3) 
      { 
       Console.Clear(); 
       Console.WriteLine("Thank you for using my program, Good bye !!!"); 
       // break; 
      } 

      //topmenu(); 
      } 
     while (useroption != 3); 




     Console.ReadKey(); 


    } 

    //This method present the user with an menu which the user has a choice of 3 options 
    static int topmenu() 
    { 
     int option; 
     string option_str; 

     Console.Clear(); 
     Console.WriteLine("********************************************************************************"); 
     Console.WriteLine("********************************************************************************"); 
     Console.WriteLine("*********  OPTION 1 : Enter your name        *********"); 
     Console.WriteLine("*********  OPTION 2 : Enter the number you want to factorise  *********"); 
     Console.WriteLine("*********  OPTION 3 : Quit           *********"); 
     Console.WriteLine("********************************************************************************"); 
     Console.WriteLine("********************************************************************************"); 
     option_str = Console.ReadLine(); 

     option = Convert.ToInt32(option_str); 
     Console.Clear(); 

     if (option < 0 || option > 3) 
     { 
      Console.WriteLine("You have enter an invald option,"); 
      Console.WriteLine("Please chose a option between 1-3 (Please press any key to return to main menu)"); 
      Console.ReadLine(); 
      Console.Clear(); 
      topmenu(); 
     } 
     else 
     { 
      Console.WriteLine("You have chosen option: " + option + " (Please press any key continue)"); 
     } 
     Console.ReadKey(); 
     return option; 




    } 
    //this method asks user to enter their name (1st name then surname) and presents it back to the user as their intial(1st name) and surname 
    static void Createname() 
    { 
     string firstname, surname, firstname_str, surname_str, userfullname; 

     Console.Clear(); 
     Console.WriteLine("Please enter your first name "); 
     firstname_str = Console.ReadLine(); 
     firstname = Convert.ToString(firstname_str); 
     Console.Clear(); 
     Console.WriteLine("Please enter your surname name "); 
     surname_str = Console.ReadLine(); 
     surname = Convert.ToString(surname_str); 
     Console.Clear(); 
     userfullname = firstname + surname; 

     Console.WriteLine("You have entered your name as " + firstname[0] + "." + surname); 
     Console.WriteLine("(Please press any key to return to main menu)"); 
     Console.ReadKey(); 
     topmenu(); 

    } 

    //this method asks the user to enter a number and returns the factorial of that number 
    static double factorial() 
    { 


     string number_str; 
     double factorial = 1; 



     Console.WriteLine("Please enter number"); 
     number_str = Console.ReadLine(); 

     int num = Convert.ToInt32(number_str); 


     // If statement is used so when the user inputs 0, INVALID is outputed 

     if (num <= 0) 
     { 
      Console.WriteLine("You have enter an invald option"); 
      Console.WriteLine("Please enter number"); 
      number_str = Console.ReadLine(); 
      Console.Clear(); 


      num = Convert.ToInt32(number_str); 
      //Console.Clear(); 
      //topmenu(); 
      //number_str = Console.ReadLine(); 
     } 

     if (num >= 0) 
     { 

      while (num != 0) 
      { 
       for (int i = num; i >= 1; i--) 
       { 
        factorial = factorial * i; 
        Console.Write(i + " * "); 

       } 


        Console.WriteLine("= "+factorial+ " which is factorial of " + number_str.ToString()); 
        Console.WriteLine("(please any key to return to main menu)"); 
        Console.ReadKey(); 
        Console.Clear(); 
        topmenu(); 

      } 

     } 


     return factorial; 




    } 
} 

}

Answer 1

只要把這些線內做......而

int useroption; 
useroption = topmenu(); 

重新排列如下...

int useroption; 
     // excute while loop untill option is not 1-3 
     do 
     { 

      useroption = topmenu(); 

和你的程序將正常工作

完整的代碼是在這裏： http://pastebin.com/fCh0ttUY

Answer 2

人首先，設置useroption到0執行一些代碼後。否則它將繼續執行它。其次，ReadKey（）就在while語句之前。否則，你將無法讀取輸入。

Answer 3

問題是，儘管您再次顯示topmenu y你永遠不要重新分配有用的價值。

正如gypsyCoder所說，在do {} while（）塊內移動菜單的顯示將解決您的問題，因爲它會導致循環中每次循環重新分配用途。