Lignes aléatoires

• Pour que la trace suive la souris, cliquer sur la forme, maintenir le bouton droit et déplacer.
• Relâcher pour terminer.

Lignes droites

• Pour tirer des lignes droites, cliquer sur la forme au point de départ et maintenir le bouton, déplacer la souris au point d'arrivée et relâcher le bouton.

Option Explicit
Const PS_SOLID = 0
Const Epp = 10 'épaisseur du trait

Private Type POINTAPI
  X As Long
  Y As Long
End Type
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function CreatePen Lib "gdi32" (ByVal nPenStyle As Long, ByVal nWidth As Long, ByVal crColor As Long) As Long
Private Declare Function LineTo Lib "gdi32" (ByVal hdc As Long, ByVal X As Long, ByVal Y As Long) As Long
Private Declare Function MoveToEx Lib "gdi32" (ByVal hdc As Long, _
  ByVal X As Long, ByVal Y As Long, lpPoint As Any) As Long


Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
    DeleteObject SelectObject(Me.hdc, CreatePen(PS_SOLID, Epp, RGB(0, 255, 0)))
    MoveToEx Me.hdc, X, Y, &H0
End Sub

'Mettre ce code dans Form_MouseUp pour une ligne droite
'sans la ligne >> If Button <> 1 Then Exit Sub
Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
    If Button <> 1 Then Exit Sub
    DeleteObject SelectObject(Me.hdc, CreatePen(PS_SOLID, Epp, RGB(0, 255, 0)))
    LineTo Me.hdc, X, Y
    Me.Refresh
End Sub