'自定义函数：顾名思义，就是自己定义的函数。
'为什么使用自定义函数：exce内置了很多有用的函数。但仍无法满足工作需求。
'自定义函数的作用：简化复杂的公式。可以和工作表函数相互嵌套使用
'
'
' Function 函数名(参数1,参数2....)
' 代码
' 函数名=代码执行的结果
' End Function
'
'1.函数名称可能有函数，也可以像now,today,rand等函数一样不需要任何参数
Public Function stname()
stname = ActiveSheet.Name '返回当前工作表名
End Function
Public Function wbname()
wbname = ThisWorkbook.Name '返回工作簿名
End Function
'有参数的自定义函数
Function nas(num As Integer) '提取工作表名或工作簿名
If num = 0 Then
nas = ActiveSheet.Name
ElseIf num = 1 Then
nas = ThisWorkbook.Name
End If
End Function
'1.自定义工作函数的调用
Function wbname()
wbname = ActiveWorkbook.Name
End Function
Function wbnames()
i = InStr(wbname, ".xls") '调用自定义的工作表函数，找到.xls所在的位置
j = Left(wbname, i - 1) '调用自定义的工作表函数
wbnames = j
End Function
'2.自定义工作表函数的编写与运用范围
'
'自定义工作表函数的代码只能编写在：标准模块中，不能在工作表中或thisworkbook中
'到目前为止我们编写的自定义函数只能在当前工作簿运行。要在所有工作簿中运行则：
'A.将编写在标准模块中的自定义函数代码保存为：加载宏。
'B.将加载的宏保持运用即可
'
'提示：与应用程序事件程序的操作方法相似
案例：
参数不定的自定义函数：
参数值默认和参数缺省：
案例：返回不重复随机数（结果是数组）
Function sjs(最小值 As Integer, 最大值 As Integer, 所需个数 As Integer)
Application.Volatile
Set d = CreateObject("scripting.dictionary")
Do
i = Application.RandBetween(最小值, 最大值)
d(i) = ""
Loop Until d.Count = 所需个数
sjs = d.keys
End Function
Sub dd()
Set d = CreateObject("scripting.dictionary")
Do
i = Application.RandBetween(1, 9)
d(i) = ""
Loop Until d.Count = 4
sj = d.keys
End Sub
案例2：
Function celljoin(区域 As Range, Optional 合并符 As String = "-")
arr = Application.Transpose(Application.Transpose(区域))
celljoin = Join(arr, 合并符)
End Function
Function 去除(rng As Range, Optional shuzi As Integer = 2)
Set regx = CreateObject("vbscript.regexp")
With regx
.Global = True
If shuzi = 0 Then
.Pattern = "\d" '去数字
ElseIf shuzi = 1 Then
.Pattern = "[a-zA-Z]" '去字母
ElseIf shuzi = 2 Then
.Pattern = "[一-龢]" '去汉字
End If
去除 = .Replace(rng, "")
End With
End Function
案例3：
Function jia(ParamArray num())
For Each n In num
m = m + n
Next
jia = m
End Function
Function joins(ParamArray arr())
For Each ar In arr
For Each a In ar
txt = txt & a.Value
Next
Next
joins = txt
End Function
'注意：
'1.如果参数不定，那么不能指定参数的数据类型
'2.如果有不定参数，不定参数一定要写在最后。
'
案例3：
Function 身份证(rng As Range, Optional 提取内容 As String = "年龄")
If 提取内容 = "年龄" Then
身份证 = Year(Now()) - (19 & Mid(rng, Len(rng) / 2, 2))
ElseIf 提取内容 = "性别" Then
身份证 = IIf(Mid(rng, 15, 3) Mod 2, "男", "女")
End If
End Function
下图用excel：
案例4：单元颜色求和(字典+自定义函数)
Function COLORSUM(单元格区域 As range, 汇总的颜色 As range)
Set d = CreateObject("Scripting.Dictionary")
For Each Rng In 汇总的颜色
d(Rng.Interior.ColorIndex) = ""
Next
For Each ci In d.keys
For Each Rng In 单元格区域
If Rng.Interior.ColorIndex = ci Then
r = r + Rng.Value
End If
Next
Next
COLORSUM = r
End Function
Sub test()
Set d = CreateObject("Scripting.Dictionary")
Set 区域 = Application.InputBox("区域选择", , , , , , , 8)
Set 颜色 = Application.InputBox("颜色选择", , , , , , , 8)
For Each Rng In 颜色
d(Rng.Interior.ColorIndex) = ""
Next
For Each ci In d.keys
For Each Rng In 区域
If Rng.Interior.ColorIndex = ci Then
r = r + Rng.Value
End If
Next
Next
MsgBox r
End Sub
Function DD(rng As Range) '反转字符
For i = Len(rng) To 1 Step -1
a = Mid(rng, i, 1)
b = b & a
Next
DD = b
End Function
Function 求和(rng As Range, Optional s As String = "")
Application.Volatile
Set regx = CreateObject("vbscript.regexp")
With regx
.Global = True
.Pattern = "\d" & s
Set mat = .Execute(rng)
End With
For Each m In mat
n = n + m * 1
Next
求和 = n
End Function
Function 不重复值(rng As Range)
Set d = CreateObject("scripting.dictionary")
For Each rn In rng
d(rn.Value) = ""
Next
不重复值 = d.keys
End Function
Function 不重复2(rng As Range, Optional num As Integer = 0)
Set d = CreateObject("scripting.dictionary")
Set regx = CreateObject("vbscript.regexp")
With regx
.Global = True
If num = 0 Then
.Pattern = ".+" '所有值的不重复
ElseIf num = 1 Then
.Pattern = "[一-龢]+" '汉字不重复
ElseIf num = 2 Then
.Pattern = "[a-zA-Z]+" '字母不重复
ElseIf num = 3 Then
.Pattern = "\d+" '数字不重复
End If
For Each rn In rng
For Each m In .Execute(rn)
d(m.Value) = ""
Next
Next
不重复2 = d.keys
End With
End Function
ByVal是值传递，ByRef是地址传递
回顾11章中的内容:
ByVal是值传递，ByRef是地址传递
好了，参数讲完，回归，function用法：
http://xixiacademy.com/html/ExcelVBA/Function/ExcelVBA_VolatileFunction.html