Question

vb里子函数如何定义，调用？

Private Function Maxmod_(ByVal a As Long, ByVal b As Long) _
As Long

Dim p As Long
p = a Mod b
If p = b Then Maxmod = b
Else: Maxmod = Maxmod(b, p)
End Function

Private Sub Command1_Click()
Dim a As Long
Dim b As Long
Dim answer As Long
a = Val(Text1.Text)
b = Val(Text2.Text)
answer = Maxmod(a, b)
Print answer

End Sub

我这个代码在运行的时候报错，说我Maxmod没有定义，为啥？

Answer 1

先说下问题:
1,你调用的函数名和定义的函数名不一样 应改为一致
2,你的 if ...else 这个语句块不对,缺少 end if
3,你这是个递归函数,你的词句在不断的调用后,最终会使b(除数)为0.这样系统就会报错 应该在Maxmod()中添加一句当b=1时,让其退出函数.
修改后的函数如下,希望对你有所帮助
Private Function Maxmod(ByVal a As Long, ByVal b As Long) _
As Long
If b = 1 Then
Exit Function
End If
Dim p As Long
p = a Mod b
If p = b Then
Maxmod = b
Else
Maxmod = Maxmod(b, p)
End If
End Function

Private Sub Command1_Click()
Dim a As Long
Dim b As Long
Dim answer As Long
a = Val(Text1.Text)
b = Val(Text2.Text)
answer = Maxmod(a, b)
Print answer

End Sub

Answer 2

1,你调用的函数名和定义的函数名不一样 应改为一致
2,你的 if ...else 这个语句块不对,缺少 end if
3,你这是个递归函数,你的词句在不断的调用后,最终会使b(除数)为0.这样系统就会报错 应该在Maxmod()中添加一句当b=1时,让其退出函数.
修改后的函数如下,希望对你有所帮助
Private Function Maxmod(ByVal a As Long, ByVal b As Long) _
As Long
If b = 1 Then
Exit Function
End If
Dim p As Long
p = a Mod b
If p = b Then
Maxmod = b
Else
Maxmod = Maxmod(b, p)
End If
End Function

Private Sub Command1_Click()
Dim a As Long
Dim b As Long
Dim answer As Long
a = Val(Text1.Text)
b = Val(Text2.Text)
answer = Maxmod(a, b)
Print answer
End Sub

Answer 3

代码有问题 仔细点 我修改的 就不会错 你多个——
Private Function Maxmod(ByVal a As Long, ByVal b As Long) As Long

Dim p As Long
p = a Mod b
If p = b Then
Maxmod = b
Else
Maxmod = Maxmod(b, p)
end if
End Function

Private Sub Command1_Click()
Dim a As Long
Dim b As Long
Dim answer As Long
a = Val(Text1.Text)
b = Val(Text2.Text)
answer = Maxmod(a, b)
Print answer

End Sub

Answer 4

当然了，你定义的函数实际上是“Maxmod_”，多了个“_”