API-PolylineTo绘制曲线

Option Explicit
Dim X As Double
Private Type POINTAPI
X As Long
y As Long
End Type
Private Declare Function PolylineTo Lib "gdi32" (ByVal hdc As Long, ByVal lppt As POINTAPI, ByVal cCount As Long) As Long
Private Declare Function MoveToEx Lib "gdi32" (ByVal hdc As Long, ByVal X As Long, ByVal y As Long, ByVal lpPoint As Any) As Long
Private Sub Form_Load()
Timer1.Interval = 100
Me.ScaleMode = vbPixels
X = 0.1
AutoRedraw = True
End Sub
Private Sub draw()
Dim Pt(1 To 1000) As POINTAPI, A As Double, R As Double
Dim N As Long, Xm As Long, Ym As Long
Xm = Me.ScaleWidth / 2
Ym = Me.ScaleHeight / 2
For N = 1 To 1000
A = N * X
R = R + A * 0.01
Pt(N).X = Xm + Cos(A) * R
Pt(N).y = Ym - Sin(A) * R
Next N
MoveToEx Me.hdc, Me.ScaleWidth / 2, Me.ScaleHeight / 2, ByVal 0&
PolylineTo Me.hdc, Pt(1), 100
End Sub
Private Sub Form_Paint()
draw
End Sub
Private Sub Timer1_Timer()
X = X + 0.01
Me.Caption = X
Me.Cls
Form_Paint
End Sub