Connect Four Horizontal winner - vb.net

Question

I'm creating a connect four game and I'm having some trouble with the horizontal loop. The loop below works and it's for a vertical win. I have a two labels for each row and two labels for each column one for the color blue and one for the color red. When I add in my other labels I cant seem to find where I take the step-1 in order to change labels and go upwards with the next label. I have also tried adding a whole new loop below that just dedicated to the horizontal winnings.
For i = 5 To 0 Step -1`
If board(i, 0) = 0 Then
board(i, 0) = pturn
If pturn = 1 Then
Labelboard(i, 0).BackColor = Color.Red
CounterB = 0
lblcounterBlue.Text = "Matches = " & CounterB
CounterR = CounterR + 1
lblCounterRed.Text = "Matches = " & CounterR
ElseIf pturn = 2 Then
Labelboard(i, 0).BackColor = Color.Blue
CounterR = 0
lblCounterRed.Text = "Matches = " & CounterR
CounterB = CounterB + 1
lblcounterBlue.Text = "Matches = " & CounterB
End If
pturn = pturn + 1
If pturn = 3 Then pturn = 1
If CounterR = 4 Then
MsgBox("Game Over")
End If
If CounterB = 4 Then
MsgBox("Game Over")
End If
Exit Sub
End If
Next

Answer 1

I don't quite understand your setup, but hopefully this will get you close enough for you to get things working. I'm having to make a few assumptions, but I've tried to declare a constant each time I have to make the code more readable and easier for you to adapt to what you've already written.
What I've written is a function that lets you know if a specific space is part of winning streak. It assumes board() is public. If pturn is also public, you could make this even more efficient as long as you call it every turn, as noted in the comments. If you know which space was the last one played, you can maximize efficiency by only calling the function for that space (assuming you call it at the end of every player turn). If you don't know which space was played last, you can loop through every space in board() and test each one.
Function winner(rowNum As Integer, colNum As Integer) As Integer
'Returns 0 if space does not create a win, or the winning player number if it does
'Change to winner(...) As Boolean <--To only test current player
Dim minRow As Integer = LBound(board, 0)
Dim maxRow As Integer = UBound(board, 0)
Dim minColumn As Integer = LBound(board, 1)
Dim maxColumn As Integer = UBound(board, 1)
'These are the values I assume are in board()
'(I don't actually use them in the code)
Const emptySpace As Integer = 0
Const red As Integer = 1
Const blue As Integer = 2
Dim player As Integer
Dim streak As Integer
Dim r As Integer, c As Integer 'loop placeholders
Dim v As Integer, h As Integer 'control search direction
For v = 0 To 1
For h = -1 To 1
If v = 1 Or h = 1 Then
'These loops and test check each direction (vertical, horizontal and
'both diagonals) for a win exactly once.
player = board(rowNum, colNum)
If player > 0 Then 'If player = pturn <-- to only check current player
streak = 1
'check positive direction
r = rowNum + h
c = colNum + v
Do While r >= minRow And r <= maxRow And c >= minColumn And c <= maxColumn
If board(r, c) = player Then
streak = streak + 1
If streak = 4 Then
Return player 'True <--If testing only current player
Else
r = r + h
c = c + v
End If
Else
Exit Do
End If
Loop
'check negative direction
r = rowNum - h
c = colNum - v
Do While r >= minRow And r <= maxRow And c >= minColumn And c <= maxColumn
If board(r, c) = player Then
streak = streak + 1
If streak = 4 Then
Return player 'True <--If testing only current player
Else
r = r - h
c = c - v
End If
Else
Exit Do
End If
Loop
End If
End If
Next h
Next v
Return 0 'Function has completed and no winner was found
'Return False <-- If only testing current player
End Function