“定时器与分支语句的应用”实践指导
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer) If KeyCode = 39 Then Timer1.Enabled = True Image3.Visible = False Image4.Visible = False End If If KeyCode = 37 Then Timer3.Enabled = True Image1.Visible = False Image2.Visible = False End If End Sub Private Sub Form_KeyUp(KeyCode As Integer, Shift As Integer) If KeyCode = 39 Then Timer1.Enabled = False End If If KeyCode = 37 Then Timer3.Enabled = False End If End Sub Private Sub Form_Load() Image1.Top = 4920 Image1.Left = 0 Image2.Top = 4920 Image2.Left = 0 Image3.Top = 4920 Image3.Left = 0 Image4.Top = 4920 Image4.Left = 0 Image1.Visible = True Image2.Visible = False Image3.Visible = False Image4.Visible = False End Sub Private Sub Timer1_Timer() Image1.Left = Image1.Left + 100 Image2.Left = Image2.Left + 100 Image3.Left = Image3.Left + 100 Image4.Left = Image4.Left + 100 If Image1.Left > 9600 Then Image1.Left = 0 Image2.Left = 0 End If If Image1.Visible = False Then Image1.Visible = True Image2.Visible = False Else Image1.Visible = False Image2.Visible = True End If If Image1.Left > 7320 And Image1.Left < 8880 Then Timer1.Enabled = False Timer2.Enabled = True End If End Sub Private Sub Timer2_Timer() Image1.Visible = False Image2.Visible = True Image1.Top = Image1.Top + 50 Image2.Top = Image2.Top + 50 If Image1.Top > 6300 Then Image1.Top = 4920 Image1.Left = 0 Image2.Top = 4920 Image2.Left = 0 Timer1.Enabled = True Timer2.Enabled = False End If End Sub Private Sub Timer3_Timer() Image1.Left = Image1.Left - 100 Image2.Left = Image2.Left - 100 Image3.Left = Image3.Left - 100 Image4.Left = Image4.Left - 100 If Image3.Visible = False Then Image3.Visible = True Image4.Visible = False Else Image3.Visible = False Image4.Visible = True End If End Sub Private Sub Timer4_Timer() '起 Image1.Left = Image1.Left + 100 Image2.Left = Image2.Left + 100 Image3.Left = Image3.Left + 100 Image4.Left = Image4.Left + 100 Image1.Top = Image1.Top - 50 Image2.Top = Image2.Top - 50 Image3.Top = Image3.Top - 50 Image4.Top = Image4.Top - 50 End Sub