Convert int to enum

Before converting a number to an enumeration, you must check whether the number belongs to an enumeration in order not to go beyond the enum and not get unexpected code behavior due to an unexpected value:

 int number = 1; if (Enum.IsDefined(typeof(CustomEnum), number)) { CustomEnum enm = (CustomEnum)number; // преобразование // или CustomEnum enm = (CustomEnum)Enum.ToObject(typeof(CustomEnum), number); } 

MSDN documentation:

1. Enum.IsDefined
2. enum (C # Reference)
3. Enumeration Types (C # Programming Guide)
4. Enum.TryParse

From the MSDN documentation example:

 using System; [Flags] enum Colors { None=0, Red = 1, Green = 2, Blue = 4 }; public class Example { public static void Main() { string[] colorStrings = { "0", "2", "8", "blue", "Blue", "Yellow", "Red, Green" }; foreach (string colorString in colorStrings) { Colors colorValue; if (Enum.TryParse(colorString, out colorValue)) if (Enum.IsDefined(typeof(Colors), colorValue) | colorValue.ToString().Contains(",")) Console.WriteLine("Converted '{0}' to {1}.", colorString, colorValue.ToString()); else Console.WriteLine("{0} is not an underlying value of the Colors enumeration.", colorString); else Console.WriteLine("{0} is not a member of the Colors enumeration.", colorString); } } } // The example displays the following output: // Converted '0' to None. // Converted '2' to Green. // 8 is not an underlying value of the Colors enumeration. // blue is not a member of the Colors enumeration. // Converted 'Blue' to Blue. // Yellow is not a member of the Colors enumeration. // Converted 'Red, Green' to Red, Green. 

In the example, the Enum.IsDefined check takes place. To protect your code from possible errors is not a sign of a bad programming tone, I think.