解析:
其实比较简单啦,用一个窗体就可以实现啦!
我自己写的,你可以看看
Option Explicit
Dim strNumber As String
Dim strPoint As String
Dim dblNum1 As Double
Dim intOperator As Integer
'清除结果绝敏
Private Sub cmdGT_Click()
txtDisplay.Text = "0."
strNumber = ""
strPoint = "."
intOperator = 7
End Sub
'输入数字
Private Sub cmdNumber_Click(Index As Integer)
strNumber = strNumber &cmdNumber(Index).Caption
txtDisplay.Text = strNumber &strPoint
End Sub
Private Sub cmdOnOff_Click()
End
End Sub
'运算过程
Private Sub cmdOperator_Click(Index As Integer)
Dim dblnum2 As Double
'是第一次单击运算符时并告枝，将输入的值先赋给第一个数，否则赋值给第二个数进行运算
If intOperator = 7 Then
dblNum1 = CDbl(txtDisplay.Text)
Else
dblnum2 = CDbl(Val(txtDisplay.Text))
'根据输入的符号进行运算
'求普通运算
Select Case intOperator
Case 0
dblNum1 = dblNum1 + dblnum2
Case 1
dblNum1 = dblNum1 - dblnum2
Case 2
dblNum1 = dblNum1 * dblnum2
Case 3
If dblnum2 <>0 Then
dblNum1 = dblNum1 / dblnum2
Else
MsgBox "除数不能为“0”！请友贺重新输入除数。", vbOKOnly + vbInformation, "除零错误"
Index = intOperator
End If
Case 6
dblNum1 = dblNum1 * dblnum2 / 100
End Select
End If
'取得当前输入的运算符，以做下次运算
intOperator = Index
strNumber = ""
txtDisplay = CStr(dblNum1)
'判断是否为文本框中的数字加点
If Not txtDisplay Like "*.*" Then
txtDisplay.Text = txtDisplay.Text &"."
End If
End Sub
Private Sub cmdOtherOper_Click(Index As Integer)
Dim dblNum As Double
'求平方根，平方，
dblNum = CDbl(Val(txtDisplay.Text))
Select Case Index
Case 0
'验证数据是否有效
If dblNum >= 0 Then
txtDisplay.Text = CStr(Sqr(dblNum))
Else
MsgBox "负数不能开平方根！", _
vbOKOnly + vbCritical, "开平方根错误"
End If
Case 1
txtDisplay.Text = CStr(dblNum ^ 2)
End Select
'判断是否为文本框中的数字加点
If Not txtDisplay Like "*.*" Then
txtDisplay.Text = txtDisplay.Text &"."
End If
End Sub
Private Sub cmdPoint_Click()
strNumber = strNumber &strPoint
strPoint = ""
End Sub
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
'使被按下的数字键的对应按钮取得焦点
Select Case KeyCode
Case 48 To 57
cmdNumber(KeyCode - 48).SetFocus
Case 96 To 105
cmdNumber(KeyCode - 96).SetFocus
Case Else
'使按下的符号键对应的按钮取得焦点
If KeyCode = 107 Or (Shift = vbShiftMask And KeyCode = 187) Then
cmdOperator(0).SetFocus
cmdOperator_Click (0)
ElseIf KeyCode = 109 Or KeyCode = 189 Then
cmdOperator(1).SetFocus
cmdOperator_Click (1)
ElseIf KeyCode = 106 Or (Shift = vbShiftMask And KeyCode = 56) Then
cmdOperator(2).SetFocus
cmdOperator_Click (2)
ElseIf KeyCode = 111 Or KeyCode = 191 Then
cmdOperator(3).SetFocus
cmdOperator_Click (3)
ElseIf KeyCode = 13 Then
cmdOperator(7).SetFocus
cmdOperator_Click (7)
ElseIf KeyCode = 8 Then
cmdGT.SetFocus
Call cmdGT_Click
End If
End Select
End Sub
Private Sub Form_KeyPress(KeyAscii As Integer)
'将合法的数据输入到文本框
Select Case KeyAscii
Case 48 To 58
'调用数字键点击处理程序
cmdNumber_Click KeyAscii - 48
KeyAscii = 0
Case 46
'调用小数点输入
cmdPoint_Click
KeyAscii = 0
Case 13
'当敲击回车时，不能触发Form的 KeyUp 事件，因此在这里设置文本框的焦点
txtDisplay.SetFocus
Case Else
KeyAscii = 0
End Select
End Sub
Private Sub Form_KeyUp(KeyCode As Integer, Shift As Integer)
txtDisplay.SetFocus
End Sub
Private Sub Form_Load()
strNumber = ""
strPoint = "."
intOperator = 7
End Sub
代码如下：
Dim t, t1 As Integer
Dim x, y As Double
Public Sub com()
x = Val(l1.Caption)
Select Case t1
Case Is = 1: y = y + x
Case Is = 2: y = y - x
Case Is = 3: y = y * x
Case Is = 4: y = y / x
End Select
t1 = 0
t = 0
l1.Caption = "0"
End Sub
Private Sub Form_Load()
x = 0
y = 0
t = 0
t1 = 1
End Sub
Private Sub c0_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "0"
Else
l1.Caption = l1.Caption + "0"
End If
End Sub
Private Sub C1_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "1"
Else
l1.Caption = l1.Caption + "1"
End If
End Sub
Private Sub c10_Click(Index As Integer)
If t = 0 Then
l1.Caption = l1.Caption + "."弊含
t = 1
End If
End Sub
Private Sub C2_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "2"
Else
l1.Caption = l1.Caption + "租卖笑2"
End If
End Sub
Private Sub C3_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "3"
Else
l1.Caption = l1.Caption + "3"
End If
End Sub
Private Sub C4_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "4"
Else
l1.Caption = l1.Caption + "4"
End If
End Sub
Private Sub C5_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "5"
Else
l1.Caption = l1.Caption + "5"
End If
End Sub
Private Sub C6_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "配尘6"
Else
l1.Caption = l1.Caption + "6"
End If
End Sub
Private Sub C7_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "7"
Else
l1.Caption = l1.Caption + "7"
End If
End Sub
Private Sub C8_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "8"
Else
l1.Caption = l1.Caption + "8"
End If
End Sub
Private Sub C9_Click(Index As Integer)
If l1.Caption = "0" Then
l1.Caption = "9"
Else
l1.Caption = l1.Caption + "9"
End If
End Sub
Private Sub z1_Click(Index As Integer)
com
t1 = 1
End Sub
Private Sub z2_Click(Index As Integer)
com
t1 = 2
End Sub
Private Sub z3_Click(Index As Integer)
com
t1 = 3
End Sub
Private Sub z4_Click(Index As Integer)
com
t1 = 4
End Sub
Private Sub z5_Click(Index As Integer)
tmp = Mid(l1.Caption, Len(l1.Caption), 1)
If tmp = "." Then
t = 0
End If
If Len(l1.Caption) = 1 Then
l1.Caption = "0"
Else
l1.Caption = Left(l1.Caption, Len(l1.Caption) - 1)
End If
End Sub
Private Sub z6_Click(Index As Integer)
l1.Caption = "0"
Form_Load
End Sub
Private Sub z7_Click(Index As Integer)
If (l1.Caption <>"0") Then
l1.Caption = "-" + l1.Caption
End If
End Sub
Private Sub z8_Click(Index As Integer)
com
l1.Caption = Str(y)
End Sub
扩展资料语言缺点
Visual Basic 语言具有不支持继承、无原生支持多线程、异常处理不完善等三项明显缺点，使其有所局限性（此些缺点皆已在 vb .net 获得改进）。
不支持继承
VB 5.0 和 VB 6.0 都是基于对象的编程语言，但是不包含继承特性。VB 中提供了特殊的类的功能，但是还是不能满足程序员的需求。
无原生支持多线程
Visual Basic 对于多线程无原生支持，只能通过Windows API的调用实现，且极其的不稳定。因为在API创建的线程中，并没有自动初始化运行时库，导致部分的函数无法使用。一般的，在VB6等早期的VB开发环境下，使用API创建线程的目的是完成容易使程序假死的大量数据或者逻辑的计算。
异常处理不完善
Visual Basic 中内置异常处理，即使未写异常处理代码，一旦用户出错也会d出一个明确写出出错原因对话框，接着程序终止。
Visual Basic 中可以使用 Err.Raise抛出异常。对系统及用户抛出的异常的处理常用两种模式：一是使用 On Error Resume Next 处理错误；另一种是使用 On Error Goto 将运行引入错误处理代码。但相对 C++ 等语言而言，这样的异常处理破坏了代码的结构。
参考资料：百度百科-VB
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