Question

关于组合框的VB题，求大神解答啊~

窗体上建立一个简单组合框，在组合框的文本框中输入数字字符，按回车加入到组合框的列表框内，单击交换按钮。将列表框中的最小值和第0个项目交换，最大值与最后项目交换。组合框中的值为23，345,9,33,98,123,77,44,55（因为没办法截图，就只能写数据了`）

Answer 1

这个问题，先将ComboBox中的数字全部保存到数组，利用数组进行操作应该方便一些。
Private Sub Command1_Click()
Dim a() As Long
ReDim a(Combo1.ListCount - 1)
For i = 0 To Combo1.ListCount - 1
a(i) = CLng(Combo1.List(i)) '将Combo1中的值全部装入数组a()
Next
Dim m As Long, mi As Integer
Dim n As Long, ni As Integer
Dim t As Long
m = CLng(Combo1.List(0))
n = m
mi = 0
ni = 0
For i = 1 To Combo1.ListCount - 1
If CLng(Combo1.List(i)) > m Then m = CLng(Combo1.List(i)): mi = i 'm 为数组中的最大值
If CLng(Combo1.List(i)) < n Then n = CLng(Combo1.List(i)): ni = i 'n 为数组中的最小值
Next
t = a(ni)
a(ni) = a(0)
a(0) = t '将数组中的最小值与数组元素(0)处的值交换
t = a(mi)
a(mi) = a(UBound(a))
a(UBound(a)) = t '将数组中的最大值与数组元素中最后一个值交换
Combo1.Clear '将COmbo1清空
For i = 0 To UBound(a) '重新将数组a()添加到Combo1中
Combo1.AddItem a(i)
Next
Combo1.Text = Combo1.List(0)
End Sub

Answer 2

Private Sub Combo1_KeyPress(KeyAscii As Integer)

If KeyAscii = 13 Then

Combo1.AddItem Combo1.Text
Combo1.Text = ""

End If

End Sub

Private Sub Command1_Click()

Dim i As Integer
Dim Max As Integer
Dim Min As Integer
Dim temp As Integer

Max = 0: Min = 0

For i = 1 To Combo1.ListCount - 1

If Val(Combo1.List(Max)) < Val(Combo1.List(i)) Then Max = i
If Val(Combo1.List(Min)) > Val(Combo1.List(i)) Then Min = i

Next i

temp = Combo1.List(0)
Combo1.List(0) = Combo1.List(Min)
Combo1.List(Min) = temp
temp = Combo1.List(Combo1.ListCount - 1)
Combo1.List(Combo1.ListCount - 1) = Combo1.List(Max)
Combo1.List(Max) = temp

End Sub