如何不可能为数组分配值，同时又不可能分别分配每个数组元素呢？

Question

I m working on a Unity3D project and using the Mesh class,
inside the Mesh class there is a member variable Vector3[] vertices .
Now, while setting mesh.vertices in the following way is possible

Vector3[] v = new Vector3[3];
v[0] = new Vector3[0,0,0];
v[1] = new Vector3[1,1,1];
v[2] = new Vector3[2,2,2];
mesh.vertices = v; 

setting an individual element, like this: mesh.vertices[0] = new Vector3(1,1,1) seems to have no effect.
(also, mesh.vertices[0].x = 5 have no effect as well).
When i say no effect i mean that the code does compile and run with no errors, but the elements of the array are not changing.
Since the vertices represent a surface, It seems logical that the designer wanted for all them to be changed together.

I have tried to mimic this magical functionality with a simple code to no avail.
What am i missing?
Is it something with Properties?
Indexers?
Some weird combination?

class Student
{
  private int[] grades = {92, 99, 96};
  public int[] Grades{
      get{
          Console.WriteLine("getter: ");
          return grades;
      }
      set{
          Console.WriteLine("setter: ");
          grades = value;
      }
  }
}

class HelloWorld
{
  static void Main ()
  {
    int[] low_grades = {53, 51, 55};
    Student student = new Student();
    student.Grades = low_grades; // This assignment is possible and this is O.K.
    student.Grades[0] = 52;  // This assignment is Possible and this is NOT O.K.
  }
}

How can i make it possible for the client to assign an array to my member variable, but to stop him from assigning values to individual elements in the array?

Answer 1

If you don't want direct access to set elements, make it a private field and provide a method to set the array. If you want you can also provide a method to return a copy of the array as a separate reference.