VB自制计算器

使用visual basic编写。
绘制如下的按钮界面：

然后代码如下：

Dim a, temp, ans As Integer
Dim op As String


Sub showans()
    Text1.Text = a
End Sub

Sub clearans()
    Text1.Text = " "
End Sub


Private Sub Command1_Click()
'按钮1

a = a * 10 + 1
Call showans
End Sub

Private Sub Command10_Click()
'按钮0
a = a * 10
Call showans

End Sub

Private Sub Command11_Click()
'按钮=
If op = "+" Then
a = temp + a
ElseIf op = "-" Then
a = temp - a
ElseIf op = "*" Then
a = temp * a
ElseIf op = "/" Then
If a <> 0 Then
a = temp / a
Else
MsgBox ("Divisor can't be zero!")
End If
End If
Call showans
temp = a
End Sub

Private Sub Command12_Click()
'按钮CE
a = 0
Call showans
End Sub

Private Sub Command13_Click()
'按钮+
temp = a
a = 0
op = "+"
Call clearans
End Sub

Private Sub Command14_Click()
'按钮-
temp = a
a = 0
op = "-"
Call clearans
End Sub

Private Sub Command15_Click()
'按钮*
temp = a
a = 0
op = "*"
Call clearans
End Sub

Private Sub Command16_Click()
'按钮/
temp = a
a = 0
op = "/"
Call clearans
End Sub

Private Sub Command2_Click()
'按钮2
a = a * 10 + 2
Call showans
End Sub

Private Sub Command3_Click()
'按钮3
a = a * 10 + 3
Call showans
End Sub

Private Sub Command4_Click()
'按钮4
a = a * 10 + 4
Call showans
End Sub

Private Sub Command5_Click()
'按钮5
a = a * 10 + 5
Call showans
End Sub

Private Sub Command6_Click()
'按钮6
a = a * 10 + 6
Call showans
End Sub

Private Sub Command7_Click()
'按钮7
a = a * 10 + 7
Call showans
End Sub

Private Sub Command8_Click()
'按钮8
a = a * 10 + 8
Call showans
End Sub

Private Sub Command9_Click()
'按钮9
a = a * 10 + 9
Call showans
End Sub

Private Sub Form_Load()
a = 0
temp = 0
ans = 0

End Sub

解释说明：
a表示当前的结果，temp表示上一个运算数
例如：
1+2，依次按下1，+，2，按下加号后temp=1,a=2，执行=键的运算时temp+a就是1+2=3
因为之后还要使用3进行计算，所以，需要将temp=a，这时再输入+2，就是3+2=5

效果展示：