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1、第6章 过程,Sub过程（子过程） 事件过程：系统定义过程名 通用过程：用户定义过程名,6-1 子过程（事件过程的定义）,Sub过程（子过程） 事件过程：系统定义过程名,Private Sub Form_MouseMove 有参数 (Button As Integer, Shift As Integer, X As Single, Y As Single) If Button=1 Then Pset (X,Y) End Sub,Private Sub Form_Load() 无参数 End Sub,6-1子过程（事件过程的调用）,窗体上按下左键移动鼠标(10,10),实参1,*,10,10,6
2、-1 子过程（通用过程）,通用过程：用户定义(完成特定功能) 定义 .形参 调用（过程的使用）实参 参数传递,6-1-1 Sub过程的定义,在代码窗口中任意位置定义 Private Sub 过程名（形式参数列表） End Sub 根据程序需要，决定有参数或无参数列表 设置形式参数列表， a As Integer, b As Integer,6-1-1 Sub过程的定义,过程名： showInfo 功 能：在窗体表面显示 * Welcome to BJFU *,Private Sub showInfo() 无参数 Print “* Welcome to BJFU *“ End Sub,6-1-1
3、 Sub过程的定义,过程名： showInfo 功 能：在窗体表面显示任意字符串str变量的内容,Private Sub showInfo(str As String) 有参数 Print str End Sub,6-1-1 Sub过程的定义,Private Sub sum(n As Integer) End Sub,For i = 1 To n result = result + i Next i Print result,Dim i As Integer, result As Integer,求1n之间所有整数的和，并显示在窗体上,6-1-1 Sub过程的调用(无参),无参情况 Priva
4、te Sub showInfo() 无参数 Print “* Welcome to BJFU *“ End Sub,Call showInfo showInfo,Call 过程名 过程名,6-1-1 Sub过程的调用(无参),Private Sub Command1_Click() Call showInfo End Sub Private Sub Form_Click() showInfo End Sub,单击窗体和command1时在窗体表面显示 * Welcome to BJFU *,6-1-1 Sub过程的调用(有参),有参情况 Private Sub sum(n As Integer
5、) Dim i As Integer, result As Integer For i = 1 To n result = result + i Next i Print result End Sub,Call 过程名 (实参表) 过程名 实参表,Call sum(22) sum 22,6-1-2 Sub过程的调用(有参),Private Sub Command1_Click() Call sum(22) End Sub Private Sub Form_Click() sum 11 End Sub,Private Sub sum (n As Integer) End Sub,Private
6、Sub sum (n As Integer) End Sub,形参,实参,实参,6-1-2 Sub过程的调用(有参),Private Sub sum(n As Integer) Dim i As Integer, result As Integer For i = 1 To n result = result + i Next i Print result End Sub,Private Sub Form_Click() Dim number As Integer number = Val(Text1.Text) sum number End Sub,形参,实参,实参是变量的情况,6-1-2
7、Sub过程的调用(有参),Private Sub Form_Click() Dim a As Integer, b As Integer a = 1: b = 2 Call add(a, b) End Sub Private Sub add(n As Integer, m As Integer) Dim result As Integer result = n + m Print result End Sub,实参是变量的情况,6-1-3 参数传递,形参名字前有传参方式： ByRef 按照地址传参（可省略） 形参的改变影响实参 ByVal 按照值传参 形参的改变不影响实参,6-1-3 参数传递
8、(ByRef),Private Sub Form_Click() Dim a As Integer a=2 Call add(a) Print a End Sub Private Sub add(ByRef n As Integer) n = n + 1 End Sub,a的值跟n值变化相同,形参的改变影响实参,3,6-1-3 参数传递(ByVal),Private Sub Form_Click() Dim a As Integer a=2 Call add(a) Print a End Sub Private Sub add(ByVal n As Integer) n = n + 1 End
9、 Sub,a的值跟n值变化无关,形参的改变不影响实参,2,6-1-3 参数传递,Private Sub sum( ByRef n As Integer) Dim i As Integer, result As Integer For i = 1 To n result = result + i Next i Print result End Sub,Private Sub Form_Click() Dim number As Integer number = Val(Text1.Text) sum number End Sub,number的值跟n值变化相同,最好采用那种方式传参？,ByVal
10、,6-1-3 参数传递,Private Sub Form_Click() Dim a As Integer, b As Integer a = 1: b = 2 Call add(a, b) End Sub Private Sub add(n As Integer, m As Integer) Dim result As Integer result = n + m Print result End Sub,最好采用那种方式传参？,ByVal n As Integer, ByVal m As Integer,6-1-3 参数传递,2! +4! + 6! + 8! + 10! Sub fact(n As Integer, f As Long) End Sub 求n的阶乘，保存到f中,
