变幻线.frm

河北工业大大一至大二学期

VERSION 5.00
Begin VB.Form frmMain 
   Caption         =   "Form1"
   ClientHeight    =   6240
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   7410
   LinkTopic       =   "Form1"
   ScaleHeight     =   6240
   ScaleWidth      =   7410
   StartUpPosition =   3  '窗口缺省
   Begin VB.Timer Timer1 
      Enabled         =   0   'False
      Interval        =   50
      Left            =   6600
      Top             =   3840
   End
   Begin VB.CommandButton Command2 
      Caption         =   "停止"
      Height          =   495
      Left            =   6240
      TabIndex        =   2
      Top             =   5280
      Width           =   1095
   End
   Begin VB.CommandButton Command1 
      Caption         =   "开始"
      Height          =   495
      Left            =   6240
      TabIndex        =   1
      Top             =   4560
      Width           =   1095
   End
   Begin VB.PictureBox Picture1 
      BackColor       =   &H00000000&
      ForeColor       =   &H00FFFFFF&
      Height          =   6015
      Left            =   120
      ScaleHeight     =   5955
      ScaleWidth      =   5955
      TabIndex        =   0
      Top             =   120
      Width           =   6015
   End
End
Attribute VB_Name = "frmMain"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Dim x1 As Long, x2 As Long, x3 As Long, x4 As Long
Dim y1 As Long, y2 As Long, y3 As Long, y4 As Long
Dim d1 As Long, d2 As Long, d3 As Long, d4 As Long
Dim iBrightness As Long, iDeltaBrightness As Long
Const Lft = 300
Const Rgt = 5655
Const Tp = 300
Const Btm = 5655

Private Sub Command1_Click()
Timer1.Enabled = True
End Sub

Private Sub Command2_Click()
Timer1.Enabled = False
End Sub

Private Sub Form_Load()
x1 = Lft: y1 = 2700: d1 = 4
x2 = 2400: y2 = Tp: d2 = 3
x3 = 4200: y3 = Btm: d3 = 1
x4 = Rgt: y4 = 3600: d4 = 2
Randomize
iBrightness = 255
iDeltaBrightness = -5
End Sub

Sub DrawLines()
Picture1.Line (x1, y1)-(x2, y2)
Picture1.Line (x2, y2)-(x3, y3)
Picture1.Line (x3, y3)-(x4, y4)
Picture1.Line (x4, y4)-(x1, y1)
End Sub

Private Sub Timer1_Timer()
Picture1.ForeColor = RGB(iBrightness, iBrightness, iBrightness)
Picture1.Cls
movepoint x1, y1, d1
movepoint x2, y2, d2
movepoint x3, y3, d3
movepoint x4, y4, d4
DrawLines
iBrightness = iBrightness + iDeltaBrightness
If iBrightness < 127 Then iDeltaBrightness = 5: iBrightness = 127
If iBrightness > 255 Then iDeltaBrightness = -5: iBrightness = 255
End Sub

Sub movepoint(ByRef px, ByRef py, ByRef d)
Const Spd As Long = 120
Select Case d
Case 1
    px = px + Rnd * Spd
    If px > Rgt Then px = Rgt: d = d + 1
Case 2
    py = py - Rnd * Spd
    If py < Tp Then py = Tp: d = d + 1
Case 3
    px = px - Rnd * Spd
    If px < Lft Then px = Lft: d = d + 1
Case 4
    py = py + Rnd * Spd
    If py > Btm Then py = Btm: d = d - 3
End Select
End Sub