How to create an array of PictureBoxes and use it? - vb.net

Question

I thought "brickn()" will creat an array and "NoOfBrick" will be the array length and all array will store in it
Dim brickWidth as Integer = 0
Dim Brickn() As PictureBox
dim NoOfBrick as Integer ' array length
Public Function CreateBrick() As PictureBox
Dim myBrickn As New PictureBox
With myBrickn
.Size = Brick.Size
.Left = BrickWidth
.Top = 0
.Image = Brick.Image
.SizeMode = PictureBoxSizeMode.StretchImage
.BackColor = Color.Black
End With
Return myBrickn
End Function
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
For i = -75 To Me.Width
Brickn(NoOfBrick) = CreateBrick() 'and also how to add array/list here
Me.Controls.Add(Brickn(NoOfBrick))
BrickWidth += 170 'increasing brick.left on every new brick is created
i += 170 ' increasing looop count according to brick needed
NoOfBrick +=1
Next
End Sub
But this code is throwing error on "Me.Controls.Add(Brickn(NoOfBrick))"
this error
System.NullReferenceException: 'Object reference not set to an instance of an object.'
I thought if I will get array of PictureBoxes then I can access control on them for this
Private Sub Boll_control_Tick(sender As Object, e As EventArgs) Handles Boll_control.Tick
If Ball.Bounds.IntersectsWith(brickn(NoOfBrick).Bounds) Then
Me.Controls.Remove(brickn(NoOfBrick))
End If
End Sub

Answer 1

Change:
Dim Brickn() As PictureBox
To:
Dim Brickn As New List(Of PictureBox)
Then, when you want to Add something to "Brickn", you'd do:
Brickn.Add(CreateBrick())
You can still access "Brickn" with array syntax, such as:
Brickn(NoOfBrick).Bounds
The difference is that a List will automatically grow or shrink in size as you add/remove things to it, while an Array has a fixed size (you never actually created the array in your code and gave it a size).
You can do hit testing with something like:
Dim hit = Brickn.Where(Function(brick) Ball.Bounds.IntersectsWith(brick.Bounds))
For Each brick As PictureBox In hit
Me.Controls.Remove(brick)
Brickn.Remove(brick)
Next