Question

VB：在窗体上自由画圆：鼠标按下为圆心，放开为圆上一点画圆。颜色由一个列表框设置。

用MouseDown及Mouse

Answer 1

Dim OldX As Single
Dim OldY As Single

Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
Me.PSet (X, Y)
OldX = X
OldY = Y
End Sub

Private Sub Form_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
Me.Circle (OldX, OldY), Sqr((OldX - X) ^ 2 + (OldY - Y) ^ 2), vbRed
End Sub