Time for action – creating the StarField class

1. Add a new class file called StarField.vb to the Asteroid Belt Assault project.

2. Add the following declarations to the StarField class:

   Private stars As List(Of Sprite) = new List(Of Sprite)
   Private screenWidth As Integer = 800
   Private screenHeight As Integer = 600
   Private rand As Random = new Random()
   Private colors As Color() = { Color.White, Color.Yellow,
                                 Color.Wheat, Color.WhiteSmoke,
                                 Color.SlateGray}

3. Add a constructor to the StarField class:

   Public Sub New(
           screenWidth As Integer,
           screenHeight As Integer,
           starCount As Integer,
           starVelocity As Vector2,
           texture As Texture2D,
           frameRectangle As Rectangle)
       Me.screenWidth = screenWidth
       Me.screenHeight = screenHeight
       For x As Integer = 0 to starCount
           stars.Add(new Sprite(
               new Vector2(CSng(rand.Next(0,screenWidth)), 
                   CSng(rand.Next(0,screenHeight...