刘金玉的零基础VB教程068期：贪吃蛇游戏开发第四节
随机生成彩色食物
食物生成
1、用到RGB函数
2、RND随机数
3、食物可以当做一个对象，那么我们可以定义一颗食物的类型，拥有坐标X，Y，颜色R,G,B
4、RGB颜色也可以定义一个类型
5、生成的食物必须在窗口内
课堂总结
1、画食物的代码写到哪里？每一次蛇的运动实际上是把界面给cls清除，我们只有每次清除后再画出来，才能看到我们的食物
2、如何保证食物生成后的位置不变？保证食物的数据位置是在全局变量中，才能保证食物位置不变
界面效果：
源代码：
Private Type Node '每一节蛇身 D As Integer '37左38上39右40下 X As Single 'left Y As Single 'top End Type Dim W As Integer '每一节蛇身宽度 Dim sno() As Node '声明一条蛇，是动态数组 Dim currentDirect As Integer '代表蛇运动的当前方向 Private WithEvents timer1 As Timer '定义颜色类型 Private Type Color R As Integer G As Integer B As Integer End Type '定义食物类型 Private Type Food X As Single Y As Single C As Color End Type '声明食物 Dim goods As Food '初始化一条蛇的各个参数 Function init() AutoRedraw = True '自动重绘 W = 200 currentDirect = 39 '默认向右运动 ReDim sno(5) As Node '初始化各个坐标点 Dim i As Long For i = 0 To UBound(sno) Step 1 sno(i).D = currentDirect sno(i).X = ScaleWidth / 2 + i * W sno(i).Y = ScaleHeight / 2 Next i '初始化食物数据 Call rndFood End Function '随机生成食物数据 Function rndFood() Randomize goods.X = Int(Rnd * (ScaleWidth - W)) goods.Y = Int(Rnd * (ScaleHeight - W)) goods.C.R = Int(Rnd * 256) goods.C.G = Int(Rnd * 256) goods.C.B = Int(Rnd * 256) End Function '画食物 Function drawFood() Line (goods.X, goods.Y)-(goods.X + W, goods.Y + W), RGB(goods.C.R, goods.C.G, goods.C.B), BF End Function '画一条蛇 Function drawSnake() Cls Dim i As Long For i = 0 To UBound(sno) Step 1 Line (sno(i).X, sno(i).Y)-(sno(i).X + W, sno(i).Y + W), vbBlue, BF Next i End Function Private Sub Form_KeyUp(KeyCode As Integer, Shift As Integer) If Abs(currentDirect - KeyCode) <> 2 Then currentDirect = KeyCode End Sub Private Sub Form_Load() Call init Call drawSnake '对时钟控件进行初始化 Set timer1 = Controls.Add("vb.timer", "timer1") timer1.Interval = 100 timer1.Enabled = True End Sub '运动思路：插入头结点，删除尾节点 Function sport() Dim i As Long '将每一个节点数据向前移动一位 For i = 1 To UBound(sno) Step 1 sno(i - 1) = sno(i) Next i '将头结点，也就是数组的最后一位重新复制 If currentDirect = 37 Then sno(UBound(sno)).X = sno(UBound(sno)).X - W ElseIf currentDirect = 38 Then sno(UBound(sno)).Y = sno(UBound(sno)).Y - W ElseIf currentDirect = 39 Then sno(UBound(sno)).X = sno(UBound(sno)).X + W ElseIf currentDirect = 40 Then sno(UBound(sno)).Y = sno(UBound(sno)).Y + W End If End Function Private Sub timer1_Timer() Call sport Call drawSnake '判断是否撞到窗体边缘 If isCrashWall Then If MsgBox("GAME OVER ！是否重新开始？", vbYesNo, "游戏结束") = vbYes Then Call init Else End End If End If '画食物 Call drawFood End Sub '是否撞到窗体边缘，撞到返回true，否则就是false Function isCrashWall() As Boolean isCrashWall = False If sno(UBound(sno)).X + W > ScaleWidth _ Or sno(UBound(sno)).X < 0 _ Or sno(UBound(sno)).Y < 0 _ Or sno(UBound(sno)).Y + W > ScaleHeight Then isCrashWall = True '撞到了 End If End Function
