>>329
Private mX As Single, mY As Single

Private Sub Form_Load()
Me.AutoRedraw = True
Picture1.Visible = False
Picture1.AutoSize = True
End Sub

Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
Picture1.Picture = Me.Image
mX = X: mY = Y
End Sub

Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Static sX As Single, sY As Single
If Button And vbLeftButton Then
Me.Picture = Picture1.Image
Me.Line (mX, mY)-(X, Y), , B
sX = X: sY = Y
End If
End Sub

Private Sub Form_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
Me.Refresh
End Sub

PictureBoxをフォームに貼り付けて、実行してね。応用力が大事だよ（はぁと