Dynamically change the Value of enum in C#?

Question

I have a enum

    public enum TestType:int
   {
      Aphasia = 2,
      FocusedAphasia = 5
   }

with values set. I want to change the value of the enum 'FocusedAphasia' from 5 to 10. Can anyone help me in changing the value of enum at runtime

Answer 1

You cannot change enums at runtime. I'm not sure why you'd ever need to, but in any case it's not possible. Using a variable would be the alternative.

Answer 2

You can't do this, it is a strongly-typed value , if you like.

The elements of the enum are read-only and changing them at runtime is not possible, nor would it be desirable.

What might suit you is extension of the enum to expose a new value to use with new features and whatnot, such as:

public enum TestType:int
{
    Aphasia = 2,
    FocusedAphasia = 5
    SomeOtherAphasia = 10
}

Not being quite clued up on exactly what you want to do, I can't well suggest much else.

Answer 3

Well actually you can. Say you have an assembly (dll) with the original TestType. You can unload that assembly (this is somewhat complicated), rewrite the assembly with a new TestType and reload it.

You can not, however, change the type of existing variables because those have to be disposed of before the assembly can be unloaded.

Answer 4

Well, this question is 7 years far while I am writing my answer. I still want to write it, maybe it will be useful for someone later.

Changing enum values in runtime is not possible, but there is a way to play around by casting int variable into enum, and defining those ints with their values in a dictionary as in below:

// Define enum TestType without values
enum TestType{}
// Define a dictionary for enum values
Dictionary<int,string> d = new Dictionary<int,string>();
void Main()
{
    int i = 5;
    TestType s = (TestType)i;
    TestType e = (TestType)2;

    // Definging enum int values with string values
    d.Add(2,"Aphasia");
    d.Add(5,"FocusedAphasia");

    // Results:
    Console.WriteLine(d[(int)s]); // Result: FocusedAphasia
    Console.WriteLine(d[(int)e]); // Result: Aphasia
}

In this way, you have a dynamic dictionary for enum values without any written inside it. In case you want any other value for the enum, then you can make a method to add it:

public void NewEnumValue(int i, string v)
{
    try
    {
        string test = d[i];
        Console.WriteLine("This Key is already assigned with value: " + 
                           test);
    }
    catch
    {
        d.Add(i,v);
    }
}

So, your last code in use should be this way:

// Define enum TestType without values
enum TestType{}
// Define a dictionary for enum values
Dictionary<int,string> d = new Dictionary<int,string>();

public void NewEnumValue(int i, string v)
{
    try
    {
        string test = d[i];
        Console.WriteLine("This Key is already assigned with value: " + 
                           test);
    }
    catch
    {
        d.Add(i,v);
        Console.WriteLine("Addition Done!");
    }
}

void Main()
{
    int i = 5;
    TestType s = (TestType)i;
    TestType e = (TestType)2;

    // Definging enum int values with string values

    NewEnumValue(2,"Aphasia");
    NewEnumValue(5,"FocusedAphasia");
    Console.WriteLine("You will add int with their values; type 0 to " +
                      "exit");
    while(true)
    {
        Console.WriteLine("enum int:");
        int ii = Convert.ToInt32(Console.ReadLine());
        if (ii == 0) break;
        Console.WriteLine("enum value:");
        string v = Console.ReadLine();
        Console.WriteLine("will try to assign the enum TestType with " + 
                          "value: " + v + " by '" + ii + "' int value.");
        NewEnumValue(ii,v);
    }

    // Results:
    Console.WriteLine(d[(int)s]); // Result: FocusedAphasia
    Console.WriteLine(d[(int)e]); // Result: Aphasia
}