咨询数据类型不匹配问题

[山水无言]

Sub test()
’通过下面6句把一个数组传递给cheng函数，则在cheng函数的sigma = sigma + CLng(val)处提示数据“类型不匹配”，我原来是sigma = sigma + val，提示类型不匹配，于是修改为sigma = sigma + CLng(val)，还是提示类型不匹配。什么原因？怎么修改呢？

Dim x As Variant
Dim sz(1 To 3) As Variant
For x = 1 To 3
sz(x) = x
Next x
MsgBox cheng(sz)

‘直接用下面语句调用，cheng函数能正常返回结果
'MsgBox cheng(1, 2, 3, 4, 5, 6)
End Sub

Function cheng(ParamArray vals() As Variant)
Dim val As Variant
Dim sigma As Long
sigma = 0
For Each val In vals
'MsgBox TypeName(val)
'MsgBox TypeName(sigma)
sigma = sigma + CLng(val)
Next
cheng = sigma
End Function

[山水无言]

ParamArray怎么用呢？ Function cheng(ParamArray vals() As Variant) Dim val As Variant Dim sigma As Long sigma = 0 For Each val In vals Debug.Print val '循环里只留这一条，仍然提示数据类型不匹配 Next cheng = sigma End Function Function cheng(ParamArray vals() As Variant) Dim val As Variant Dim sigma As Long sigma = 0 For Each val In vals 'MsgBox TypeName(val) 'MsgBox TypeName(sigma) 'sigma = sigma + CLng(val) 'Debug.Print val Debug.Print 1 '不适用val变量，只是打印1到立即窗口，可是for each ... in不会循环 Next cheng = sigma End Function

[dsd999]

Function cheng(vals() As Variant)