How to check If a Enum contain a number?

Solution 1:

The IsDefined method requires two parameters. The first parameter is the type of the enumeration to be checked. This type is usually obtained using a typeof expression. The second parameter is defined as a basic object. It is used to specify either the integer value or a string containing the name of the constant to find. The return value is a Boolean that is true if the value exists and false if it does not.

enum Status
{
    OK = 0,
    Warning = 64,
    Error = 256
}

static void Main(string[] args)
{
    bool exists;

    // Testing for Integer Values
    exists = Enum.IsDefined(typeof(Status), 0);     // exists = true
    exists = Enum.IsDefined(typeof(Status), 1);     // exists = false

    // Testing for Constant Names
    exists = Enum.IsDefined(typeof(Status), "OK");      // exists = true
    exists = Enum.IsDefined(typeof(Status), "NotOK");   // exists = false
}

SOURCE

Solution 2:

Try this:

IEnumerable<int> values = Enum.GetValues(typeof(PromotionTypes))
                              .OfType<PromotionTypes>()
                              .Select(s => (int)s);
if(values.Contains(yournumber))
{
      //...
}