If op1.Value = True Then c = 7
Label1.Caption = divsum(c)
If op2.Value = True Then a = 3
Label1.Caption = divsum(a)这两句if....then 都没有end if，相当于每个条件句都只到当行结束。这样，如果op1.value=true时，a实际上等于0，执行到 Label1.Caption = divsum(a)句时就会报错。同理，op1.value=false时，c=0，执行Label1.Caption = divsum(c)当然也会出错。把这段改成：If op1.Value...
'd=0肯定就不用算吧，加一句退出Public Function divsum(d As Integer)
Dim i As Integer, o As Integer
if d=0 then divsum=0:exit function '退出，结果为0
o = 0
For i = 500 To 600 ...
Dim c As Integer, a As IntegerPublic Function divsum(d As Integer)
Dim i As Integer, o As Integer
o = 0
For i = 500 To 600
If i Mod d = 0 Then o = o + i...
