Unity3d learning notes-1 (C ＃ learning)

2022/2/10

The starting point ： stay ts Common tools and methods in ： Get an array , Random return of a value in an array

step1：

        public static T RandomArray<T>(T[] arr)
        {
            Random random = new Random();
            int index = random.Next(0, arr.Length);

            return arr[index];
        }

step2：

        It is found that what needs to be random is an enumeration type , Convert enumeration type to array , I tried to write it myself , It is found that there are methods that can be called directly
        Enum.GetValues(typeof(Animal));

But its return type is Array, After finding , This is the base class of array type , Try turning it into an enumerated array , The attempt failed , There is no way （ Base class cannot be converted to derived class ？）

step3：

         After an attempt to convert to an array failed , introduce List

        List<Animal> animal_arr = new List<Animal>(Enum.GetValues(typeof(Animal)).Length);

step 4：

        introduce List Later, it was found that the original generic tool method could not be used , So it is overloaded , But the return can only use object 了

        public static object RandomArray(Array arr)
        {

            Random random = new Random((int)DateTime.Now.Ticks);
            int index = random.Next(0, arr.Length);
            return arr.GetValue(index);
        }

Summarize questions ：

doubt 1：
How to convert an enumeration type directly to an array of enumeration types ？

doubt 2：

obtain Array How to convert to a subclass after a type ？