编写一个求1+2+3+……n的函数sum(用VB编程)

编写一个求1+2+3+……n的函数sum,然后调用从键盘上输入一个n值，调用sum函数,求1+2+3+……100的值。

程序要求：

（1程序运行结果如图。

（2）n的值由inputbox函数输入。

(3)事件代码由窗体的单击事件触发。

Private Sub Form_Click() '对form的click事件添加代码.
Dim N As Integer
N = InputBox("输入n=")

Print "1+2+3+……" & N & "= " & sum(N)
End Sub

Public Function sum(N As Integer) As Integer 'sum函数.
s = 0
For i = 1 To N
s = s + i
Next i
sum = s
End Function

Private Sub Command1_Click() Dim int1 As Integer Dim int2 As Integer Dim i As Integer int1 = InputBox("", "请输入一个最大值") int2 = int1 For i = 1 To int1 int1 = int1 + i Next i Print "1+2+3...+" & int2 & "= " & int1 End Sub

Private Sub Form_Click() n = CInt(InputBox("请输入n:", "提示")) If n < 0 Then MsgBox "n值不正确!": Exit Sub s = 0 For i = 1 To n s = s + i Next i Print "1+2+3+...+" & n & "= " & s End Sub