Erreur "Impossible de convertir le type 'int' en 'chaîne'"

Question

Je faisais cet extrait de code simple pour générer le nom du mois en utilisant le numéro de jour, mais j'ai reçu l'erreur Cannot implicitly convert type 'int' to 'string'. Je n'essaie pas de changer MonthName en int!

class Module04 
{ 
    public static void Exercise01() 
    { 
     Console.WriteLine("Please Enter a day number between 1 and 365: "); 
     string line = Console.ReadLine(); 
     int dayNum = int.Parse(line); 

     int monthNum = 0; 

     if (dayNum <= 31) // January 
     { 
      goto End; 
     } 
     else 
     { 
      dayNum -= 31; 
      monthNum++; 
     } 

     if (dayNum <= 28) // February 
     { 
      goto End; 
     } 
     else 
     { 
      dayNum -= 28; 
      monthNum++; 
     } 

     if (dayNum <= 31) // March 
     { 
      goto End; 
     } 
     else 
     { 
      dayNum -= 31; 
      monthNum++; 
     } 

     if (dayNum <= 30) // April 
     { goto End; } 
     else 
     { 
      dayNum -= 30; 
      monthNum++; 
     } 

     if (dayNum <= 31) // May 
     { goto End; } 
     else 
     { 
      dayNum -= 31; 
      monthNum++; 
     } 

     if (dayNum <= 30) // June 
     { goto End; } 
     else 
     { 
      dayNum -= 30; 
      monthNum++; 
     } 

     if (dayNum <= 31) // July 
     { goto End; } 
     else 
     { 
      dayNum -= 31; 
      monthNum++; 
     } 

     if (dayNum <= 31) // August 
     { goto End; } 
     else 
     { 
      dayNum -= 31; 
      monthNum++; 
     } 

     if (dayNum <= 30) // September 
     { goto End; } 
     else 
     { 
      dayNum -= 30; 
      monthNum++; 
     } 

     if (dayNum <= 31) // October 
     { goto End; } 
     else 
     { 
      dayNum -= 31; 
      monthNum++; 
     } 

     if (dayNum <= 30) // November 
     { goto End; } 
     else 
     { 
      dayNum -= 30; 
      monthNum++; 
     } 

     if (dayNum <= 31) // December 
     { goto End; } 
     else 
     { 
      dayNum -= 31; 
      monthNum++; 
     } 

    End: 

     string monthName; 

     switch (monthName) 
     { 
      case 0: 
       monthName = "January"; break; 
      case 1: 
       monthName = "February"; break; 
      case 2: 
       monthName = "March"; break; 
      case 3: 
       monthName = "April"; break; 
      case 4: 
       monthName = "May"; break; 
      case 5: 
       monthName = "June"; break; 
      case 6: 
       monthName = "July"; break; 
      case 7: 
       monthName = "August"; break; 
      case 8: 
       monthName = "September"; break; 
      case 9: 
       monthName = "October"; break; 
      case 10: 
       monthName = "November"; break; 
      case 11: 
       monthName = "December"; break; 
      default: 
       monthName = "Not yet Done"; break; 
     } 
     Console.WriteLine("{0} {1}", dayNum, monthName); 
    } 
} 

Answer 1

Il est le switch où vous l'utilisez comme un int - Vous vouliez probablement dire passer monthNum à l'instruction switch.

(aussi: Ne pas si vous avez monthNum == ... dans tous les if s dans la première partie?)

Answer 2

Modifier le passage à

switch (monthNum) 

Answer 3

Vous faites un interrupteur sur nomMois, avec int cas, C# essaie donc de convertir la chaîne en int pour correspondre aux cas.

http://msdn.microsoft.com/en-us/library/06tc147t(VS.80).aspx

Answer 4

nomMois est une chaîne de sorte que vos cas de commutation doit être une chaîne aussi.

string monthName; 

      switch (monthName) 
      { 
       case "0" : 
        monthName = "January"; break; 
       case "1" : 
        monthName = "February"; break; 
       case "2" : 
        monthName = "March"; break; 
       case "3" : 
        monthName = "April"; break; 
       case "4" : 
        monthName = "May"; break; 
       case "5" : 
        monthName = "June"; break; 
       case "6" : 
        monthName = "July"; break; 
       case "7" : 
        monthName = "August"; break; 
       case "8" : 
        monthName = "September"; break; 
       case "9" : 
        monthName = "October"; break; 
       case "10" : 
        monthName = "November"; break; 
       case "11" : 
        monthName = "December"; break; 
       default : 
        monthName = "Not yet Done"; break; 
      } 
     Console.WriteLine("{0} {1}", dayNum, monthName); 
    }