Question

Please check following code tell me what the difference between Convert.ToInt32() and int(), Why Convert.ToInt32 is showing error?

Here UserType is a enum

// Showing error constant initializer must be compile time constant
const int case1 = Convert.ToInt32(UserType.Admin); 

const int case2 = int(UserType.Admin);

Answer 1

You’re assigning a return value from a method to a constant, which is not allowed. In .Net, the value of a constant is required to be known at compile time. This is not possible if it is being assigned a value from a method call at runtime.

For the general case, you could alter this slightly and have code which is logically equivalent:

static readonly int Case1 = Convert.ToInt32(UserType.Admin);

However, a simple cast to an int is allowable with enumerations, so your second example would probably be Ok (albeit not idiomatic).