How do i set a default property for this variable?

Question

The Loc variable is underlined and says it cannot be indexed because it has no default property. Can I set a default property or is there something else I can and should do?

    Private Sub tmrLeft_Tick(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles tmrLeft.Tick
    Dim MoveSpeed As Integer = 10
    Dim Loc As Point
    If Not picPlayer.Location.X - MoveSpeed < 0 Then
        Loc = New Point(picPlayer.Location.X - MoveSpeed, picPlayer.Location.Y)
        picPlayer.Location = Loc()
    End If
End Sub

Answer 1

The problem is that you have some unnecessary parentheses. You need to change this line:

picPlayer.Location = Loc()

to this:

picPlayer.Location = Loc

Parentheses can be a little confusing in VB, since they can be used for either a method invocation or a list item index. In this context, Loc is a variable, not a method, so when you put the parentheses after it, the compiler assumes that you must be attempting to access a particular item of a list by index. But, since Loc is not an array, and it's not a list with a default index-accessible property (like List.Item , where it's the default indexer, so myList.Item(3) means the same thing as myList(3) ). So, it gives an error saying that Loc can't be indexed.

Answer 2

In programming (VBA in this case), parentheses are included when you reference a method:

This is variable

Dim Loc As Point

Dim NewPoint = Loc

This is a method

  'Function to Add Two Numbers and Then Subtract a Third Number Function SumMinus(dNum1 As Double, dNum2 As Double, dNum3 As Double) As Double SumMinus = dNum1 + dNum2 - dNum3 End Function 

Dim Result As Double

Result = SumMinus(..., ..., ...);

As you see, the parentheses give it a different meaning.

variable

method()

---

Private Sub tmrLeft_Tick(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles tmrLeft.Tick
        Dim MoveSpeed As Integer = 10
        Dim Loc As Point
        If Not picPlayer.Location.X - MoveSpeed < 0 Then
            Loc = New Point(picPlayer.Location.X - MoveSpeed, picPlayer.Location.Y)
            picPlayer.Location = Loc // Without parenthesis
        End If
    End Sub