Question

关于VB程序，求大神帮忙做一下

实验8：编写一个VB.NET程序，要求3个问题在同一个窗体内实现。在窗体上设置三个按钮，单击每个按钮，分别完成每个问题。
问题1：在窗体上放置1个文本框。在文本框中输入英文字符，单击按钮会将文本框中的所有大写字符转换为小写，所有小写字符转换为大写。如输入I Just MEET Her，则输出为i jUST meet hER。
问题2：输入一个学生的五门课的考试成绩，判断其是否为优秀。优秀的条件为：五门课成绩总分超过450分或每门课程在88以上或每门主课（前三门）的成绩都在95分以上其他课程在80分以上。
问题3：运输部门的货物运输与里程有关，距离越远，每吨货物的单价越低，假设每吨单价P与距离S之间的关系如下，
32 S<100
28 100<=S<200
P= 25 200<=S<300
22.5 300<=S<400
20 400<=S>=1000
15 S>1000

输入货物重量和运送距离后，计算相应的运费。
实验目的：学习选择结构的使用。
可不可以也说明一下，该在窗口中加入什么东西，比如“button”之类的。。。多谢哈
本人财富值不太多，抱歉只有10了哈哈

Answer 1

第一题、
Private Sub Command1_Click()
Dim a As Integer, b As String, i As Integer, c() As String
a = Len(Text1.Text)
Print a
ReDim c(a) As String
For i = 1 To a
b = Mid(Text1.Text, i, 1)
Select Case b
Case "a" To "z"
c(i) = UCase(b)
Case "A" To "Z"
c(i) = LCase(b)
Case Else
c(i) = Chr(32)
End Select

Next i
Text1.Text = ""
For i = 1 To a

Text1.Text = Text1.Text & c(i)
Next i
End Sub

2、
Private Sub Form_click()

Dim a(5) As Double, i As Integer, j As Integer, k As Integer, sum As Double
Dim flag As Boolean, how As Boolean

For i = 1 To 5
a(i) = Val(InputBox("please input", "input number"))
sum = sum + a(i)
Next i
If sum > 450 Then
flag = True
how = True
End If
For k = 1 To 5
If a(k) > 88 Then
flag = True
how = True
End If
Next k
For j = 1 To 3
If a(j) > 95 Then flag = True
Next j
For k = 4 To 5
If a(k) > 80 Then how = True
Next k
If flag = True And how = True Then
Print "excellent"
End If
End Sub

3、Private Sub Form_click()
Dim s As Single, price As Single, total As Single
s = Text1.Text
If s < 100 Then
price = 32
ElseIf 100 <= s < 200 Then
price = 28
ElseIf 200 <= s < 300 Then
price = 25
ElseIf 300 <= s < 400 Then
price = 22.5
ElseIf 400 <= s < 1000 Then
price = 20
ElseIf s > 1000 Then
price = 15
End If
total = price * s
Print total
End Sub

给分吧